Vulnerability-Lookup

GHSA-2JCC-MXV7-P3F9

Vulnerability from github – Published: 2026-07-07 23:45 – Updated: 2026-07-07 23:45

Summary

oasdiff does not enforce --allow-external-refs=false on the git-revision load path (SSRF / local file read)

Details

Summary

From v1.13.2 through v1.18.0, oasdiff did not enforce --allow-external-refs=false (library: openapi3.Loader.IsExternalRefsAllowed = false) when loading a spec from a git revision (the rev:path form, e.g. main:openapi.yaml). External $refs were resolved on that load path even when external refs were explicitly disabled, so the mitigation silently did not apply there.

Impact

A caller who set --allow-external-refs=false specifically to safely process untrusted specs remained exposed — on the git-revision load path only — to:

SSRF via $ref: "http://<internal-host>/…", and
Local file reads via $ref: "/path" or file://.

Affected callers:

CLI: oasdiff diff main:openapi.yaml HEAD:openapi.yaml --allow-external-refs=false (and breaking / changelog / summary, and the git-diff-driver) run over untrusted spec content.
Go library consumers of github.com/oasdiff/oasdiff/load that set IsExternalRefsAllowed = false and load from a git-revision source via load.NewSpecInfo.

The file and URL load paths correctly enforced the setting; only the git-revision path was affected. Callers that left external refs at the default (true) are not in scope for this advisory.

Patches

v1.18.1 enforces the external-refs policy on the git-revision path (so --allow-external-refs=false now blocks external $refs there) and returns a dedicated exit code (123) when an external $ref is refused.

Workarounds

Upgrade to v1.18.1, or
Avoid the git-revision input form when processing untrusted specs with external refs disabled.

Notes

Introduced in v1.13.2 (#832, which added $ref-chain resolution on the git-revision path); fixed in v1.18.1 (#974, #975).
The permissive default (allow-external-refs: true) and its zero-interaction exposure in CI via the GitHub Action is tracked separately in GHSA-fhj3-7267-7vv5 (oasdiff-action).

Severity

6.0 (Medium)


                  
                    CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 1.18.0"
      },
      "package": {
        "ecosystem": "Go",
        "name": "github.com/oasdiff/oasdiff"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.13.2"
            },
            {
              "fixed": "1.18.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-53508"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-693",
      "CWE-73",
      "CWE-918"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-07T23:45:05Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "## Summary\n\nFrom **v1.13.2** through **v1.18.0**, oasdiff did not enforce `--allow-external-refs=false` (library: `openapi3.Loader.IsExternalRefsAllowed = false`) when loading a spec from a **git revision** (the `rev:path` form, e.g. `main:openapi.yaml`). External `$ref`s were resolved on that load path even when external refs were explicitly disabled, so the mitigation silently did not apply there.\n\n## Impact\n\nA caller who set `--allow-external-refs=false` *specifically to safely process untrusted specs* remained exposed \u2014 on the git-revision load path only \u2014 to:\n\n- **SSRF** via `$ref: \"http://\u003cinternal-host\u003e/\u2026\"`, and\n- **Local file reads** via `$ref: \"/path\"` or `file://`.\n\nAffected callers:\n\n- **CLI:** `oasdiff diff main:openapi.yaml HEAD:openapi.yaml --allow-external-refs=false` (and `breaking` / `changelog` / `summary`, and the `git-diff-driver`) run over untrusted spec content.\n- **Go library consumers** of `github.com/oasdiff/oasdiff/load` that set `IsExternalRefsAllowed = false` and load from a git-revision source via `load.NewSpecInfo`.\n\nThe file and URL load paths correctly enforced the setting; only the git-revision path was affected. Callers that left external refs at the default (`true`) are not in scope for *this* advisory.\n\n## Patches\n\n**v1.18.1** enforces the external-refs policy on the git-revision path (so `--allow-external-refs=false` now blocks external `$ref`s there) and returns a dedicated exit code (`123`) when an external `$ref` is refused.\n\n## Workarounds\n\n- Upgrade to **v1.18.1**, or\n- Avoid the git-revision input form when processing untrusted specs with external refs disabled.\n\n## Notes\n\n- Introduced in **v1.13.2** (#832, which added `$ref`-chain resolution on the git-revision path); fixed in **v1.18.1** (#974, #975).\n- The permissive **default** (`allow-external-refs: true`) and its zero-interaction exposure in CI via the GitHub Action is tracked separately in GHSA-fhj3-7267-7vv5 (oasdiff-action).",
  "id": "GHSA-2jcc-mxv7-p3f9",
  "modified": "2026-07-07T23:45:05Z",
  "published": "2026-07-07T23:45:05Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/oasdiff/oasdiff/security/advisories/GHSA-2jcc-mxv7-p3f9"
    },
    {
      "type": "WEB",
      "url": "https://github.com/oasdiff/oasdiff/pull/832"
    },
    {
      "type": "WEB",
      "url": "https://github.com/oasdiff/oasdiff/pull/974"
    },
    {
      "type": "WEB",
      "url": "https://github.com/oasdiff/oasdiff/pull/975"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/oasdiff/oasdiff"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "oasdiff does not enforce --allow-external-refs=false on the git-revision load path (SSRF / local file read)"
}

CVE-2026-53508 (GCVE-0-2026-53508)

Vulnerability from cvelistv5 – Published: 2026-08-31 18:52 – Updated: 2026-08-31 18:58

Title

oasdiff does not enforce --allow-external-refs=false on the git-revision load path (SSRF / local file read)

Summary

oasdiff is a command-line and Go package that compares and detects breaking changes in OpenAPI specs. From version 1.13.2 through version 1.18.0, oasdiff did not enforce --allow-external-refs=false (library: openapi3.Loader.IsExternalRefsAllowed = false) when loading a spec from a git revision (the rev:path form, e.g. main:openapi.yaml). External $refs were resolved on that load path even when external refs were explicitly disabled, so the mitigation silently did not apply there. This issue has been patched in version 1.18.1.

Severity

6 (Medium)


                        
                          CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-31 18:57 UTC

CWE

CWE-73 - External Control of File Name or Path
CWE-693 - Protection Mechanism Failure
CWE-918 - Server-Side Request Forgery (SSRF)

Assigner

GitHub_M mitre root Scorecard

References

4 references

URL	Tags
https://github.com/oasdiff/oasdiff/security/advis…	x_refsource_CONFIRM
https://github.com/oasdiff/oasdiff/pull/832	x_refsource_MISC
https://github.com/oasdiff/oasdiff/pull/974	x_refsource_MISC
https://github.com/oasdiff/oasdiff/pull/975	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
oasdiff	oasdiff	Affected: >= 1.13.2, < 1.18.1

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-53508",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-31T18:57:49.502659Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-31T18:58:08.849Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "oasdiff",
          "vendor": "oasdiff",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 1.13.2, \u003c 1.18.1"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "oasdiff is a command-line and Go package that compares and detects breaking changes in OpenAPI specs. From version 1.13.2 through version 1.18.0, oasdiff did not enforce --allow-external-refs=false (library: openapi3.Loader.IsExternalRefsAllowed = false) when loading a spec from a git revision (the rev:path form, e.g. main:openapi.yaml). External $refs were resolved on that load path even when external refs were explicitly disabled, so the mitigation silently did not apply there. This issue has been patched in version 1.18.1."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 6,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "PASSIVE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-73",
              "description": "CWE-73: External Control of File Name or Path",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-693",
              "description": "CWE-693: Protection Mechanism Failure",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-918",
              "description": "CWE-918: Server-Side Request Forgery (SSRF)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-31T18:52:12.213Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/oasdiff/oasdiff/security/advisories/GHSA-2jcc-mxv7-p3f9",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/oasdiff/oasdiff/security/advisories/GHSA-2jcc-mxv7-p3f9"
        },
        {
          "name": "https://github.com/oasdiff/oasdiff/pull/832",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/oasdiff/oasdiff/pull/832"
        },
        {
          "name": "https://github.com/oasdiff/oasdiff/pull/974",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/oasdiff/oasdiff/pull/974"
        },
        {
          "name": "https://github.com/oasdiff/oasdiff/pull/975",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/oasdiff/oasdiff/pull/975"
        }
      ],
      "source": {
        "advisory": "GHSA-2jcc-mxv7-p3f9",
        "discovery": "UNKNOWN"
      },
      "title": "oasdiff does not enforce --allow-external-refs=false on the git-revision load path (SSRF / local file read)"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-53508",
    "datePublished": "2026-08-31T18:52:12.213Z",
    "dateReserved": "2026-06-09T17:05:25.059Z",
    "dateUpdated": "2026-08-31T18:58:08.849Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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Action not permitted

GHSA-2JCC-MXV7-P3F9

Summary

Impact

Patches

Workarounds

Notes

CVE-2026-53508 (GCVE-0-2026-53508)

Tags

Sightings

Nomenclature

Related by attack behaviour