CVE-2026-40470

CRITICAL EPSS 22.6%

Published Apr 23, 20262mo ago · Modified Jun 17, 20262w ago

9.9 CVSS 3.1

Critical

Published Apr 23, 2026 2mo ago

Last Modified Jun 17, 2026 2w ago

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.

CVSS Details

Base Score

9.9

Exploitability

3.1

Impact

6.0

Vector string

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L

Attack Vector Network

Attack Complexity Low

Privileges Required Low

User Interaction None

Scope Changed

Confidentiality High

Integrity High

Availability Low

Threat Intelligence

EPSS Exploit Probability

22.6% percentile

Exploit & Patch Status

No Known Exploit

No Patch Available

Weaknesses 1

CWE-79 Cross-site Scripting Injection

References 1

osv.dev https://osv.dev/vulnerability/HSEC-2024-0004

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.