01 Record
CVE-2026-77912
Stored cross-site scripting vulnerability in GitHub Enterprise Server allowed HTML attribute injection via the Markdown rendering pipeline
HighPUBLISHEDCNA: GitHub_P
CNA base score7.4 CVSS v4.0CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:P/VC:H/VI:H/VA:N/SC:L/SI:L/SA:N/AU:Y
02 Description
Stored cross-site scripting vulnerability in GitHub Enterprise Server allowed HTML attribute injection via the Markdown rendering pipeline
03 Exploitation and scoring
- Exploitation
- Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.
- SSVC decision
- Not assessed by CISA
- EPSS probability
- Not scored by EPSS
- EPSS percentile
- Not scored by EPSS
- NVD base score
- The NVD has published no score for this record
- NVD CVSS vector
- No NVD score to derive
- NVD analysis status
- Not recorded
- Red Hat severity
- No Red Hat rating. Red Hat rates the CVEs that affect its products.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2026-09-22 20:43Z1 HR AGO
- Last updated
- 2026-09-22 20:43Z1 HR AGO
- Reserved
- 2026-08-21
- Assigning CNA
- GitHub_P
- Record state
- PUBLISHED
- Severity
- High (CVSS 7.4)
- CNA CVSS vector
- CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:P/VC:H/VI:H/VA:N/SC:L/SI:L/SA:N/AU:Y
- Weaknesses
- CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')Base
- Data version
- 5.2
- Document digest
- 6c34807995530acb75e62d9ce0182c3cc746525187aed6906067caace8cff1a9
05 Affected products
VendorProductVersionsPlatforms
GitHubEnterprise Server3.17.0 to < 3.17.*, 3.18.0 to < 3.18.*, 3.19.0 to < 3.19.*, 3.20.0 to < 3.20.*, 3.21.0 to < 3.21.*, 3.22.0 to < 3.22.*—
06 References
- docs.github.comhttps://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.21
- docs.github.comhttps://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.15
- docs.github.comhttps://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.12
- docs.github.comhttps://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.8
- docs.github.comhttps://docs.github.com/en/enterprise-server@3.21/admin/release-notes#3.21.6
- docs.github.comhttps://docs.github.com/en/enterprise-server@3.22/admin/release-notes#3.22.1