CVE-2026-15996 (GCVE-0-2026-15996)
Vulnerability from cvelistv5 – Published: 2026-08-05 20:12 – Updated: 2026-08-06 13:48
VLAI
EPSS
VEX
Title
Denial of service vulnerability in GitHub Enterprise Server allowed unauthenticated service disruption via deeply nested request parameters
Summary
A denial of service vulnerability was identified in GitHub Enterprise Server that allowed an unauthenticated attacker to cause excessive CPU consumption and exhaust the pool of request-handling worker processes by sending a crafted form-encoded HTTP POST request containing deeply nested parameters. Because request parameters were parsed before routing and authentication, any POST endpoint could be used to trigger the condition, which could render the instance unresponsive. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.20.3, 3.19.7, 3.18.10, and 3.17.16.
Severity
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
- CWE-674 - Uncontrolled Recursion
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://docs.github.com/en/enterprise-server@3.17… | release-notes |
| https://docs.github.com/en/enterprise-server@3.18… | release-notes |
| https://docs.github.com/en/enterprise-server@3.19… | release-notes |
| https://docs.github.com/en/enterprise-server@3.20… | release-notes |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| GitHub | Enterprise Server |
Affected:
3.17.0 , ≤ 3.17.15
(semver)
Affected: 3.18.0 , ≤ 3.18.9 (semver) Affected: 3.19.0 , ≤ 3.19.6 (semver) Affected: 3.20.0 , ≤ 3.20.2 (semver) |
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
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