CVE-2021-22864 json
Unsafe configuration options in GitHub Pages leading to remote code execution on GitHub Enterprise Server
published 2021-03-23 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-9999
- cvss
- 8.8
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 2.6%
- EPSS 2.6% chance of exploitation in 30 days, percentile 85%
- public exploits
- 0
- none known
Summary
A remote code execution vulnerability was identified in GitHub Enterprise Server that could be exploited when building a GitHub Pages site. User-controlled configuration options used by GitHub Pages were not sufficiently restricted and made it possible to override environment variables leading to code execution on the GitHub Enterprise Server instance. To exploit this vulnerability, an attacker would need permission to create and build a GitHub Pages site on the GitHub Enterprise Server instance. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.0.3 and was fixed in 3.0.3, 2.22.9, and 2.21.17. This vulnerability was reported via the GitHub Bug Bounty program.
Patch / fix
- GitHub GitHub Enterprise Server 2.21.17, 2.22.9, 3.0.3
Exploit prediction
2.55% chance of exploitation in the next 30 days, higher than 85% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 8.8 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 6.5 | AV:N/AC:L/Au:S/C:P/I:P/A:P |
Affected products
- GitHub GitHub Enterprise Server
Classification
- Weakness
-
- CWE-77 Improper Neutralization of Special Elements used in a Command
References
Sources
- CVE List CVE-2021-22864
- NVD CVE-2021-22864
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