01 Record
CVE-2026-5921
Server-Side Request Forgery in GitHub Enterprise Server allowed extraction of sensitive environment variables via timing side-channel attack
HighPUBLISHEDCNA: GitHub_P
CNA base score8.9 CVSS v4.0CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L/E:P
02 Description
Server-Side Request Forgery in GitHub Enterprise Server allowed extraction of sensitive environment variables via timing side-channel attack
03 Exploitation and scoring
- Exploitation
- Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
- SSVC decision
- ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
- AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
- Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.
- EPSS probability
- 0.42% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 36.4% of scored records. A rank, not a probability.
- NVD base score
- 8.9 (CVSS v4.0), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- NVD analysis status
- Analyzed. NVD last modified this record on 2026-10-26.
- 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
- 2026-04-21 22:11Z6 MO AGO
- Last updated
- 2026-04-22 13:18Z6 MO AGO
- Reserved
- 2026-04-08
- Assigning CNA
- GitHub_P
- Record state
- PUBLISHED
- Severity
- High (CVSS 8.9)
- CNA CVSS vector
- CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L/E:P
- Weaknesses
- CWE-918Server-Side Request Forgery (SSRF)Base
- Data version
- 5.2
- Document digest
- a13dea3a55548ed2ec11cd312304435c132fbb1f12c96770bd4dd446cf42cf47
05 Affected products
VendorProductVersionsPlatforms
GitHubEnterprise Server3.14.0 to < 3.14.26, 3.15.0 to < 3.15.21, 3.16.0 to < 3.16.17, 3.17.0 to < 3.17.14, 3.18.0 to < 3.18.8, 3.19.0 to < 3.19.5, 3.20.0 to < 3.20.1—
06 References
- docs.github.comhttps://docs.github.com/en/enterprise-server@3.14/admin/release-notes#3.14.26
- docs.github.comhttps://docs.github.com/en/enterprise-server@3.15/admin/release-notes#3.15.21
- docs.github.comhttps://docs.github.com/en/enterprise-server@3.16/admin/release-notes#3.16.17
- docs.github.comhttps://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.14
- docs.github.comhttps://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.8
- docs.github.comhttps://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.5
- docs.github.comhttps://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.1