An improper neutralization of special elements vulnerability was identified in GitHub Enterprise Server that allowed an attacker with push access to a repository to achieve remote code execution on the instance. During a git push operation, user-supplied push option values were not properly sanitized before being included in internal service headers. Because the internal header format used a delimiter character that could also appear in user input, an attacker could inject additional metadata fields through crafted push option values. This vulnerability was reported via the GitHub Bug Bounty program and has been fixed in GitHub Enterprise Server versions 3.14.25, 3.15.20, 3.16.16, 3.17.13, 3.18.7 and 3.19.4.
https://www.theregister.com/2026/04/29/github_woah_a_genuinely_helpful/
https://www.securityweek.com/critical-github-vulnerability-exposed-millions-of-repositories/
https://www.wiz.io/blog/github-rce-vulnerability-cve-2026-3854
https://thehackernews.com/2026/04/researchers-discover-critical-github.html
https://github.com/royaleybovich/CVE-2026-3854-lab
https://github.com/HaakimSec/zero2shell-50
https://github.com/jenniferreire26/CVE-2026-3854
https://github.com/daniel30padd/CVE-2026-3854
https://github.com/ridhinva/CVE-2026-3854-GHE-RCE
https://github.com/ridhinva/Trending-Exploits-May-2026
https://github.com/ridhinva/hermes-vuln-tools
https://github.com/barmi/cve-patch-auditor
https://github.com/isagoakira/ghes-cve-scanner
https://github.com/simondankelmann/cve-2026-3854-test
https://github.com/LACHHAB-Anas/Exploit_CVE-2026-3854
https://github.com/5kr1pt/CVE-2026-3854
https://docs.github.com/en/[email protected]/admin/release-notes#3.19.4
https://docs.github.com/en/[email protected]/admin/release-notes#3.18.7
https://docs.github.com/en/[email protected]/admin/release-notes#3.17.13
https://docs.github.com/en/[email protected]/admin/release-notes#3.16.16
https://docs.github.com/en/[email protected]/admin/release-notes#3.15.20
https://docs.github.com/en/[email protected]/admin/release-notes#3.14.25
Published: 2026-03-10
Updated: 2026-04-28
Base Score: 9
Vector: CVSS2#AV:N/AC:L/Au:S/C:C/I:C/A:C
Severity: High
Base Score: 8.8
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Severity: High
Base Score: 8.7
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Severity: High
EPSS: 0.40027
Tenable Research has classified this CVE under the following Vulnerability Watch classification, which includes active and historical (inactive) classifications. You can learn more about these classifications on our blog.
Vulnerability Being Monitored