Denial of service vulnerability in GitHub Enterprise Server allowed service disruption via unauthenticated API endpoint
Published May 7, 2026
6.3
MEDIUMCVSS 4.0
EPSS 0.66%
Description
A denial of service vulnerability was identified in GitHub Enterprise Server that allowed an unauthenticated attacker to cause service disruption by sending crafted requests with deeply nested JSON payloads to an unauthenticated API endpoint. The endpoint parsed user-controlled JSON request bodies without size or depth limits, causing excessive CPU and memory consumption. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.20.2, 3.19.6, 3.18.9, 3.17.15, and 3.16.18. This vulnerability was reported via the GitHub Bug Bounty program.
Affected products
-
Affected
- ≥ 3.16.0, ≤ 3.16.17
- ≥ 3.17.0, ≤ 3.17.14
- ≥ 3.18.0, ≤ 3.18.8
- ≥ 3.19.0, ≤ 3.19.5
- ≥ 3.20.0, ≤ 3.20.1
Default status is the baseline for the product. Each version can override it (patched versions can be marked unaffected).
| Vendor | Product | Default status | Versions |
|---|---|---|---|
| GitHub | Enterprise Server | affected | Affected
|
- < 3.16.18
- ≥ 3.17.0 · < 3.17.15
- ≥ 3.18.0 · < 3.18.9
- ≥ 3.19.0 · < 3.19.6
- ≥ 3.20.0 · < 3.20.2
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
References (6)
- https://docs.github.com/en/enterprise-server@3.16/admin/release-notes#3.16.18 release-notesRelease NotesVendor Advisory
- https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.15 release-notesRelease NotesVendor Advisory
- https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.9 release-notesRelease NotesVendor Advisory
- https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.6 release-notesRelease NotesVendor Advisory
- https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.2 release-notesRelease NotesVendor Advisory
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-28462 Advisory
| Link | Providers | Tags |
|---|---|---|
| https://docs.github.com/en/enterprise-server@3.16/admin/release-notes#3.16.18 | release-notesRelease NotesVendor Advisory | |
| https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.15 | release-notesRelease NotesVendor Advisory | |
| https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.9 | release-notesRelease NotesVendor Advisory | |
| https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.6 | release-notesRelease NotesVendor Advisory | |
| https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.2 | release-notesRelease NotesVendor Advisory | |
| https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-28462 | Advisory |
Change history (0)
No recorded changes yet.
CVE.org / MITRE
CISA Vulnrichment
Red Hat
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GitHub
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