CVE-2026-8034 (GCVE-0-2026-8034)

Vulnerability from cvelistv5 – Published: 2026-05-07 21:18 – Updated: 2026-05-07 21:18
VLAI?
Title
Server-side request forgery vulnerability in GitHub Enterprise Server notebook viewer via URL parser confusion
Summary
A server-side request forgery (SSRF) vulnerability was identified in the GitHub Enterprise Server notebook viewer that allowed an attacker to access internal services by exploiting URL parser confusion between the validation layer and the HTTP request library. The hostname validation used a different URL parser than the request library, enabling a crafted URL to pass validation while directing the request to an unintended host. Exploitation required network access to the GitHub Enterprise Server instance. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.16.18, 3.17.15, 3.18.9, 3.19.6, and 3.20.2. This vulnerability was reported via the GitHub Bug Bounty program.
Severity ?
7.9 (High)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H
CWE
  • CWE-918 - Server-Side request forgery (SSRF)
  • CWE-436 - Interpretation Conflict
Assigner
References
Impacted products
Vendor Product Version
GitHub Enterprise Server Affected: 3.16.0 , ≤ 3.16.17 (semver)
Affected: 3.17.0 , ≤ 3.17.14 (semver)
Affected: 3.18.0 , ≤ 3.18.8 (semver)
Affected: 3.19.0 , ≤ 3.19.5 (semver)
Affected: 3.20.0 , ≤ 3.20.1 (semver)
Unaffected: 3.21.0 (semver)
Create a notification for this product.
Credits
R31n
Show details on NVD website
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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.



Detection rules are retrieved from Rulezet.