Common Weakness Enumeration

CWE-758

Allowed-with-Review

Reliance on Undefined, Unspecified, or Implementation-Defined Behavior

Abstraction: Class · Status: Incomplete

The product uses an API function, data structure, or other entity in a way that relies on properties that are not always guaranteed to hold for that entity.

38 vulnerabilities reference this CWE, most recent first.

GHSA-9R85-XF24-6724

Vulnerability from github – Published: 2026-03-24 15:30 – Updated: 2026-03-25 21:30
VLAI
Details

Undefined behavior in the WebRTC: Signaling component. This vulnerability affects Firefox < 149 and Firefox ESR < 140.9.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2026-4718"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-758"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-03-24T13:16:07Z",
    "severity": "HIGH"
  },
  "details": "Undefined behavior in the WebRTC: Signaling component. This vulnerability affects Firefox \u003c 149 and Firefox ESR \u003c 140.9.",
  "id": "GHSA-9r85-xf24-6724",
  "modified": "2026-03-25T21:30:27Z",
  "published": "2026-03-24T15:30:28Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-4718"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2014864"
    },
    {
      "type": "WEB",
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-20"
    },
    {
      "type": "WEB",
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-22"
    },
    {
      "type": "WEB",
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-23"
    },
    {
      "type": "WEB",
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-24"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-CH89-5G45-QWC7

Vulnerability from github – Published: 2023-04-27 17:08 – Updated: 2025-05-02 12:52
VLAI
Summary
Undefined Behavior in Rust runtime functions
Details

Impact

Wasmtime's implementation of managing per-instance state, such as tables and memories, contains LLVM-level undefined behavior. This undefined behavior was found to cause runtime-level issues when compiled with LLVM 16 which causes some writes, which are critical for correctness, to be optimized away. Vulnerable versions of Wasmtime compiled with Rust 1.70, which is currently in beta, or later are known to have incorrectly compiled functions. Versions of Wasmtime compiled with the current Rust stable release, 1.69, and prior are not known at this time to have any issues, but can theoretically exhibit potential issues.

The underlying problem is that Wasmtime's runtime state for an instance involves a Rust-defined structure called Instance which has a trailing VMContext structure after it. This VMContext structure has a runtime-defined layout that is unique per-module. This representation cannot be expressed with safe code in Rust so unsafe code is required to maintain this state. The code doing this, however, has methods which take &self as an argument but modify data in the VMContext part of the allocation. This means that pointers derived from &self are mutated. This is typically not allowed, except in the presence of UnsafeCell, in Rust. When compiled to LLVM these functions have noalias readonly parameters which means it's UB to write through the pointers.

Wasmtime's internal representation and management of VMContext has been updated to use &mut self methods where appropriate. Additionally verification tools for unsafe code in Rust, such as cargo miri, are planned to be executed on the main branch soon to fix any Rust-level issues that may be exploited in future compiler versions.

Precomplied binaries available for Wasmtime from GitHub releases have been compiled with at most LLVM 15 so are not known to be vulnerable. As mentioned above, however, it's still recommended to update.

Patches

Wasmtime version 6.0.2, 7.0.1, and 8.0.1 have been issued which contain the patch necessary to work correctly on LLVM 16 and have no known UB on LLVM 15 and earlier.

Workarounds

If Wasmtime is compiled with Rust 1.69 and prior, which use LLVM 15, then there are no known issues. There is a theoretical possibility for UB to exploited, however, so it's recommended that users upgrade to a patched version of Wasmtime. Users using beta Rust (1.70 at this time) or nightly Rust (1.71 at this time) must update to a patched version to work correctly.

References

For more information

If you have any questions or comments about this advisory:

Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "crates.io",
        "name": "wasmtime"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.0.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "crates.io",
        "name": "wasmtime"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "7.0.0"
            },
            {
              "fixed": "7.0.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "crates.io",
        "name": "wasmtime"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "8.0.0"
            },
            {
              "fixed": "8.0.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2023-30624"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-758"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2023-04-27T17:08:37Z",
    "nvd_published_at": "2023-04-27T17:15:08Z",
    "severity": "LOW"
  },
  "details": "### Impact\n\nWasmtime\u0027s implementation of managing per-instance state, such as tables and memories, contains LLVM-level undefined behavior. This undefined behavior was found to cause runtime-level issues when compiled with LLVM 16 which causes some writes, which are critical for correctness, to be optimized away. Vulnerable versions of Wasmtime compiled with Rust 1.70, which is currently in beta, or later are known to have incorrectly compiled functions. Versions of Wasmtime compiled with the current Rust stable release, 1.69, and prior are not known at this time to have any issues, but can theoretically exhibit potential issues.\n\nThe underlying problem is that Wasmtime\u0027s runtime state for an instance involves a Rust-defined structure called `Instance` which has a trailing `VMContext` structure after it. This `VMContext` structure has a runtime-defined layout that is unique per-module. This representation cannot be expressed with safe code in Rust so `unsafe` code is required to maintain this state. The code doing this, however, has methods which take `\u0026self` as an argument but modify data in the `VMContext` part of the allocation. This means that pointers derived from `\u0026self` are mutated. This is typically not allowed, except in the presence of `UnsafeCell`, in Rust. When compiled to LLVM these functions have `noalias readonly` parameters which means it\u0027s UB to write through the pointers.\n\nWasmtime\u0027s internal representation and management of `VMContext` has been updated to use `\u0026mut self` methods where appropriate. Additionally verification tools for `unsafe` code in Rust, such as `cargo miri`, are planned to be executed on the `main` branch soon to fix any Rust-level issues that may be exploited in future compiler versions.\n\nPrecomplied binaries available for Wasmtime from GitHub releases have been compiled with at most LLVM 15 so are not known to be vulnerable. As mentioned above, however, it\u0027s still recommended to update.\n\n### Patches\n\nWasmtime version 6.0.2, 7.0.1, and 8.0.1 have been issued which contain the patch necessary to work correctly on LLVM 16 and have no known UB on LLVM 15 and earlier. \n\n### Workarounds\n\nIf Wasmtime is compiled with Rust 1.69 and prior, which use LLVM 15, then there are no known issues. There is a theoretical possibility for UB to exploited, however, so it\u0027s recommended that users upgrade to a patched version of Wasmtime. Users using beta Rust (1.70 at this time) or nightly Rust (1.71 at this time) must update to a patched version to work correctly.\n\n### References\n\n* [GitHub Advisory](https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-ch89-5g45-qwc7)\n* [Mailing list announcement](https://groups.google.com/a/bytecodealliance.org/g/sec-announce/c/ecK-6G2yi90)\n\n### For more information\n\nIf you have any questions or comments about this advisory:\n\n* Reach out to us on [the Bytecode Alliance Zulip chat](https://bytecodealliance.zulipchat.com/#narrow/stream/217126-wasmtime)\n* Open an issue in [the bytecodealliance/wasmtime repository](https://github.com/bytecodealliance/wasmtime/)",
  "id": "GHSA-ch89-5g45-qwc7",
  "modified": "2025-05-02T12:52:55Z",
  "published": "2023-04-27T17:08:37Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-ch89-5g45-qwc7"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-30624"
    },
    {
      "type": "WEB",
      "url": "https://github.com/bytecodealliance/wasmtime/commit/0977952dcd9d482bff7c288868ccb52769b3a92e"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/bytecodealliance/wasmtime"
    },
    {
      "type": "WEB",
      "url": "https://groups.google.com/a/bytecodealliance.org/g/sec-announce/c/ecK-6G2yi90"
    },
    {
      "type": "WEB",
      "url": "https://rustsec.org/advisories/RUSTSEC-2023-0092.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Undefined Behavior in Rust runtime functions"
}

GHSA-CP45-6Q6C-3772

Vulnerability from github – Published: 2026-07-21 21:32 – Updated: 2026-08-18 21:31
VLAI
Details

In Eclipse OpenJ9 versions up to 0.60, when executing class files where a previously concrete superclass method has been recompiled as abstract, execution is incorrectly delegated to an interface default method.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2026-16441"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-758"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-21T19:17:09Z",
    "severity": "MODERATE"
  },
  "details": "In Eclipse OpenJ9 versions up to 0.60, when executing class files where a previously concrete superclass method has been recompiled as abstract, execution is incorrectly delegated to an interface default method.",
  "id": "GHSA-cp45-6q6c-3772",
  "modified": "2026-08-18T21:31:36Z",
  "published": "2026-07-21T21:32:39Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/eclipse-openj9/openj9/security/advisories/GHSA-hcfc-9hjx-2q7f"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-16441"
    },
    {
      "type": "WEB",
      "url": "https://github.com/eclipse-openj9/openj9/pull/24396"
    },
    {
      "type": "WEB",
      "url": "https://gitlab.eclipse.org/security/cve-assignment/-/work_items/194"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:A/VC:N/VI:H/VA:L/SC:L/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ]
}

GHSA-GFXP-F68G-8X78

Vulnerability from github – Published: 2025-09-15 13:57 – Updated: 2025-09-15 13:57
VLAI
Summary
LibYML: `libyml::string::yaml_string_extend` is unsound and unmaintained
Details

In version 0.0.4, libyml::string::yaml_string_extend was revised resulting in undefined behaviour, which is unsound.

The GitHub project for libyml was archived after unsoundness issues were raised.

If you rely on this crate, it is highly recommended switching to a maintained alternative.

Recommended alternatives

Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "crates.io",
        "name": "libyml"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.0.4"
            },
            {
              "last_affected": "0.0.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-758"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2025-09-15T13:57:29Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "In version 0.0.4, `libyml::string::yaml_string_extend` was revised resulting in undefined behaviour, which is unsound.\n\nThe GitHub project for `libyml` was archived after unsoundness issues were raised.\n\nIf you rely on this crate, it is highly recommended switching to a maintained alternative.\n\n## Recommended alternatives\n\n- [`libyaml-safer`](https://crates.io/crates/libyaml-safer) \n- [`unsafe-libyaml-norway`](https://crates.io/crates/unsafe-libyaml-norway) - Maintained fork of `unsafe-libyaml`",
  "id": "GHSA-gfxp-f68g-8x78",
  "modified": "2025-09-15T13:57:29Z",
  "published": "2025-09-15T13:57:29Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/rustsec/advisory-db/issues/2395"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/sebastienrousseau/libyml"
    },
    {
      "type": "WEB",
      "url": "https://rustsec.org/advisories/RUSTSEC-2025-0067.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "LibYML: `libyml::string::yaml_string_extend` is unsound and unmaintained"
}

GHSA-J97Q-98F4-5WQ3

Vulnerability from github – Published: 2026-03-24 15:30 – Updated: 2026-03-25 21:30
VLAI
Details

Undefined behavior in the Audio/Video component. This vulnerability affects Firefox < 149.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2026-4724"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-758"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-03-24T13:16:08Z",
    "severity": "CRITICAL"
  },
  "details": "Undefined behavior in the Audio/Video component. This vulnerability affects Firefox \u003c 149.",
  "id": "GHSA-j97q-98f4-5wq3",
  "modified": "2026-03-25T21:30:28Z",
  "published": "2026-03-24T15:30:29Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-4724"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2014865"
    },
    {
      "type": "WEB",
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-20"
    },
    {
      "type": "WEB",
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-23"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-MRXG-J2XH-WG8Q

Vulnerability from github – Published: 2026-03-24 15:30 – Updated: 2026-03-24 21:31
VLAI
Details

Undefined behavior in the WebRTC: Signaling component. This vulnerability affects Firefox < 149 and Firefox ESR < 140.9.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2026-4705"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-758"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-03-24T13:16:06Z",
    "severity": "CRITICAL"
  },
  "details": "Undefined behavior in the WebRTC: Signaling component. This vulnerability affects Firefox \u003c 149 and Firefox ESR \u003c 140.9.",
  "id": "GHSA-mrxg-j2xh-wg8q",
  "modified": "2026-03-24T21:31:22Z",
  "published": "2026-03-24T15:30:28Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-4705"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2014873"
    },
    {
      "type": "WEB",
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-20"
    },
    {
      "type": "WEB",
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-22"
    },
    {
      "type": "WEB",
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-23"
    },
    {
      "type": "WEB",
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-24"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-QG24-8XJ4-GJ2H

Vulnerability from github – Published: 2021-08-25 20:58 – Updated: 2021-08-18 20:17
VLAI
Summary
Unaligned memory allocation in chunky
Details

An issue was discovered in the chunky crate through 2020-08-25 for Rust. The Chunk API does not honor an alignment requirement.

Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "crates.io",
        "name": "chunky"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "0.3.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2020-36433"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-758"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2021-08-18T20:17:28Z",
    "nvd_published_at": "2021-08-08T06:15:00Z",
    "severity": "HIGH"
  },
  "details": "An issue was discovered in the chunky crate through 2020-08-25 for Rust. The Chunk API does not honor an alignment requirement.",
  "id": "GHSA-qg24-8xj4-gj2h",
  "modified": "2021-08-18T20:17:28Z",
  "published": "2021-08-25T20:58:13Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2020-36433"
    },
    {
      "type": "WEB",
      "url": "https://github.com/aeplay/chunky/issues/2"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/aeplay/chunky"
    },
    {
      "type": "WEB",
      "url": "https://rustsec.org/advisories/RUSTSEC-2020-0035.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Unaligned memory allocation in chunky"
}

GHSA-V57J-J5HJ-CGF3

Vulnerability from github – Published: 2025-10-02 00:32 – Updated: 2025-10-02 00:32
VLAI
Details

OpenPLC_V3 has a vulnerability in the enipThread function that occurs due to the lack of a return value. This leads to a crash when the server loop ends and execution hits an illegal ud2 instruction. This issue can be triggered remotely without authentication by starting the same server multiple times or if the server exits unexpectedly. The vulnerability allows an attacker to cause a Denial of Service (DoS) against the PLC runtime, stopping any PC started remotely without authentication. This results in the PLC process crashing and halting all automation or control logic managed by OpenPLC.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2025-54811"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-758"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-10-01T22:15:31Z",
    "severity": "MODERATE"
  },
  "details": "OpenPLC_V3 has a vulnerability in the enipThread function that occurs due to the lack of a return value. This leads to a crash when the server loop ends and execution hits an illegal ud2 instruction. This issue can be triggered remotely without authentication by starting the same server multiple times or if the server exits unexpectedly. The vulnerability allows an attacker to cause a Denial of Service (DoS) against the PLC runtime, stopping any PC started remotely without authentication. This results in the PLC process crashing and halting all automation or control logic managed by OpenPLC.",
  "id": "GHSA-v57j-j5hj-cgf3",
  "modified": "2025-10-02T00:32:09Z",
  "published": "2025-10-02T00:32:09Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-54811"
    },
    {
      "type": "WEB",
      "url": "https://github.com/thiagoralves/OpenPLC_v3"
    },
    {
      "type": "WEB",
      "url": "https://www.cisa.gov/news-events/ics-advisories/icsa-25-273-05"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ]
}

No mitigation information available for this CWE.

No CAPEC attack patterns related to this CWE.