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CVE-2026-76851 (GCVE-0-2026-76851)

Vulnerability from cvelistv5 – Published: 2026-09-01 21:55 – Updated: 2026-09-02 13:09
VLAI
Title
Server-Side Request Forgery vulnerability in GitHub Enterprise Server allowed remote code execution via network access from pre-receive hooks to internal services
Summary
A Server-Side Request Forgery (SSRF) vulnerability was identified in GitHub Enterprise Server that allowed remote code execution on the instance. Insufficient network isolation allowed malicious pre-receive hook code to impersonate an internal service and redirect trusted internal requests to a privileged service, leading to elevated code execution. Exploitation required pre-receive hook networking to be enabled and either site administrator privileges or write access to a repository containing a configured pre-receive hook. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.22 and was fixed in versions 3.17.20, 3.18.14, 3.19.11, 3.20.7, and 3.21.5. This vulnerability was reported via the GitHub Bug Bounty program.
SSVC
Exploitation: none Automatable: no Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-02 13:09 UTC
CWE
  • CWE-918 - Server-Side Request Forgery (SSRF)
Impacted products
Vendor Product Version CPE status
GitHub Enterprise Server Affected: 3.17.0 , ≤ 3.17.19 (semver)
Affected: 3.18.0 , ≤ 3.18.13 (semver)
Affected: 3.19.0 , ≤ 3.19.10 (semver)
Affected: 3.20.0 , ≤ 3.20.6 (semver)
Affected: 3.21.0 , ≤ 3.21.4 (semver)
Unaffected: 3.22.0 (semver)
guessed Create a notification for this product.
Credits
Show details on NVD website

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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.

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Detection rules are retrieved from Rulezet.

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