CVE-2026-40472: hackage-server · Cross-site Scripting
Affects hackage-serverSource CVE Database V5
Not known to be exploited · CVSS 9.9 Critical.
Data as of 30 Oct 2026, 06:59 UTC
Contested
Critical score, yet low EPSS after six months- EPSS
- 0.3% chance of exploitation in 30 days – higher than 23% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:LExploitation evidence
Disclosed: evidence found.
CVE published 23 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Hackagehackage-serverpkg:hackage/hackage-serverOther threats | Affected
| Fixed in– |
Hackagehackage-serverpkg:hackage/hackage-serverOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Until an official fix is available, users should consider restricting access to the affected hackage-server instance and avoid processing untrusted .cabal metadata. Implementing input sanitization or output encoding on href attributes may mitigate risk but should be done following vendor recommendations once available.
Description
In hackage-server, user-controlled metadata from .cabal files are rendered into HTML href attributes without proper sanitization, enabling stored Cross-Site Scripting (XSS) attacks.