CVE-2026-40470
Hackage package and doc upload stored XSS vulnerability
- State
- Published
- Severity
- 9.9 Critical
- Published
- Apr 23, 2026
- Updated
- Apr 23, 2026
- Reserved
- Apr 13, 2026
Description
A critical XSS vulnerability affected hackage-server and hackage.haskell.org. HTML and JavaScript files provided in source packages or via the documentation upload facility were served as-is on the main hackage.haskell.org domain. As a consequence, when a user with latent HTTP credentials browses to the package pages or documentation uploaded by a malicious package maintainer, their session can be hijacked to upload packages or documentation, amend maintainers or other package metadata, or perform any other action the user is authorised to do.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 9.9 Critical | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L | redhat-cnalr |
Weaknesses
- CWE-79 Improper neutralization of input during web page generation ('cross-site scripting')
Affected Products
| Product | Versions |
|---|---|
hackage-server |
|
References
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