Vulnerability-Lookup

GHSA-MPJ7-WP32-Q53H

Vulnerability from github – Published: 2026-10-05 15:32 – Updated: 2026-10-05 15:32

Details

In Progress® Telerik® Fiddler® Classic for Windows, versions prior to v6.0.20262.10021, the integrity check applied to the external helper tools launched by the application is insufficient. Before executing a helper tool, the application only verifies that the file carries a valid Authenticode signature whose certificate subject name matches a broad allow list of publisher name fragments, rather than verifying that the file is the specific executable shipped with that version of the product. A local threat actor with low privileges who replaces one of these helper executables with any other validly signed binary from an allow-listed publisher can cause the substituted binary to be executed by the application, including with Administrator privileges for the tools that request elevation, resulting in privilege escalation and execution of unintended code. Successful exploitation requires the user to launch the affected external tool and to approve the elevation prompt without noticing that it refers to a different executable.

Severity

7.9 (High)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

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JSON

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{
  "affected": [],
  "aliases": [
    "CVE-2026-77805"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-347"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-05T13:16:54Z",
    "severity": "HIGH"
  },
  "details": "In Progress\u00ae Telerik\u00ae Fiddler\u00ae Classic for Windows, versions prior to v6.0.20262.10021, the integrity check applied to the external helper tools launched by the application is insufficient. Before executing a helper tool, the application only verifies that the file carries a valid Authenticode signature whose certificate subject name matches a broad allow list of publisher name fragments, rather than verifying that the file is the specific executable shipped with that version of the product. A local threat actor with low privileges who replaces one of these helper executables with any other validly signed binary from an allow-listed publisher can cause the substituted binary to be executed by the application, including with Administrator privileges for the tools that request elevation, resulting in privilege escalation and execution of unintended code. Successful exploitation requires the user to launch the affected external tool and to approve the elevation prompt without noticing that it refers to a different executable.",
  "id": "GHSA-mpj7-wp32-q53h",
  "modified": "2026-10-05T15:32:22Z",
  "published": "2026-10-05T15:32:22Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-77805"
    },
    {
      "type": "WEB",
      "url": "https://docs.telerik.com/fiddler/knowledge-base/kb-security-weak-executable-signature-verification-cve-2026-77805"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-77805 (GCVE-0-2026-77805)

Vulnerability from cvelistv5 – Published: 2026-10-05 12:40 – Updated: 2026-10-05 15:26

Title

Weak Executable Signature Verification Vulnerability in Progress® Telerik® Fiddler® Classic

Summary

Severity

7.9 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-10-05 15:25 UTC

CWE

CWE-347 - Improper Verification of Cryptographic Signature

Assigner

ProgressSoftware mitre root Scorecard

References

1 reference

URL	Tags
https://docs.telerik.com/fiddler/knowledge-base/k…	vendor-advisory

Impacted products

1 product

Vendor	Product	Version
Progress Software	Progress® Telerik® Fiddler® Classic	Affected: 1.0.0 , < 6.0.20262.10021 (custom)

Credits

NATO Cyber Security Centre (NCSC)

Show details on NVD website

JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-77805",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-05T15:25:58.985097Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-10-05T15:26:04.778Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "platforms": [
            "Windows"
          ],
          "product": "Progress\u00ae Telerik\u00ae Fiddler\u00ae Classic",
          "vendor": "Progress Software",
          "versions": [
            {
              "lessThan": "6.0.20262.10021",
              "status": "affected",
              "version": "1.0.0",
              "versionType": "custom"
            }
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      ],
      "credits": [
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          "type": "finder",
          "value": "NATO Cyber Security Centre (NCSC)"
        }
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      "descriptions": [
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              "base64": false,
              "type": "text/html",
              "value": "In Progress\u00ae Telerik\u00ae Fiddler\u00ae Classic for Windows, versions prior to v6.0.20262.10021, the integrity check applied to the external helper tools launched by the application is insufficient. Before executing a helper tool, the application only verifies that the file carries a valid Authenticode signature whose certificate subject name matches a broad allow list of publisher name fragments, rather than verifying that the file is the specific executable shipped with that version of the product. A local threat actor with low privileges who replaces one of these helper executables with any other validly signed binary from an allow-listed publisher can cause the substituted binary to be executed by the application, including with Administrator privileges for the tools that request elevation, resulting in privilege escalation and execution of unintended code. Successful exploitation requires the user to launch the affected external tool and to approve the elevation prompt without noticing that it refers to a different executable."
            }
          ],
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        {
          "capecId": "CAPEC-206",
          "descriptions": [
            {
              "lang": "en",
              "value": "CAPEC-206 Signing Malicious Code"
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          ]
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "LOCAL",
            "availabilityImpact": "NONE",
            "baseScore": 7.9,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "CHANGED",
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        "dateUpdated": "2026-10-05T12:40:57.524Z",
        "orgId": "f9fea0b6-671e-4eea-8fde-31911902ae05",
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      "references": [
        {
          "tags": [
            "vendor-advisory"
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          "url": "https://docs.telerik.com/fiddler/knowledge-base/kb-security-weak-executable-signature-verification-cve-2026-77805"
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
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      "title": "Weak Executable Signature Verification Vulnerability in Progress\u00ae Telerik\u00ae Fiddler\u00ae Classic",
      "workarounds": [
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            }
          ],
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    "datePublished": "2026-10-05T12:40:57.524Z",
    "dateReserved": "2026-08-21T13:37:36.679Z",
    "dateUpdated": "2026-10-05T15:26:04.778Z",
    "state": "PUBLISHED"
  },
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  "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.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

GHSA-MPJ7-WP32-Q53H

CVE-2026-77805 (GCVE-0-2026-77805)

Tags

Sightings

Nomenclature

Related by attack behaviour