CVE-2026-2266 (GCVE-0-2026-2266)

Vulnerability from cvelistv5 – Published: 2026-03-10 18:55 – Updated: 2026-03-11 14:15
VLAI?
Title
Improper neutralization of input vulnerability was identified in GitHub Enterprise Server that allowed cross-site scripting via task list content and enabled arbitrary HTML injection
Summary
An improper neutralization of input vulnerability was identified in GitHub Enterprise Server that allowed DOM-based cross-site scripting via task list content. The task list content extraction logic did not properly re-encode browser-decoded text nodes before rendering, allowing user-supplied HTML to be injected into the page. An authenticated attacker could craft malicious task list items in issues or pull requests to execute arbitrary scripts in the context of another user's browser session. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.20 and was fixed in versions 3.18.6 and 3.19.3. This vulnerability was reported via the GitHub Bug Bounty program.
Severity ?
7.4 (High)
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
CWE
  • CWE-79 - Improper neutralization of input during web page generation ('cross-site scripting')
Assigner
References
Impacted products
Vendor Product Version
GitHub Enterprise Server Affected: 3.18.0 , ≤ 3.18.5 (semver)
Affected: 3.19.0 , ≤ 3.19.2 (semver)
Create a notification for this product.
Credits
André Storfjord Kristiansen
Show details on NVD website
To clipboard 

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Sightings

Author Source Type Date

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.