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CVE-2026-76851

high

A Server-Side Request Forgery (SSRF) vulnerability was identified in GitHub Enterprise Server that allowed remote code execution on the instance.

Vendor / product: Github — enterprise server

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.

CVSS
8.8
8.8 (CVSS v3.1)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Severity source: NVD CVSS v3.1 (nvd@nist.gov)
Timeline (UTC)
Published: 2026-09-01 22:17
Modified: 2026-09-08 13:05
NVD status: Analyzed
Last synced 2 days ago
Verified against the source API 2026-10-27 06:50 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).

Affected products

github / enterprise_server <3.17.20, ≥3.18.0 <3.18.14, ≥3.19.0 <3.19.11, ≥3.20.0 <3.20.7, ≥3.21.0 <3.21.5

Weakness classification (CWE)

Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.

Mitigation & advisories

Vendor advisory: https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.20
Vendor advisory: https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.14
Vendor advisory: https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.11
Vendor advisory: https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.7
Vendor advisory: https://docs.github.com/en/enterprise-server@3.21/admin/release-notes#3.21.5

References

Data sources

NVD CVE API 2.0 — fetched 2026-10-27 06:50 UTC · record ↗

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