CVE-2026-114731

Summary

Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 is affected by an uncontrolled resource consumption vulnerability in the CSS proxy (the utils/modcss action). The fetched stylesheet was read into memory in full, with no size limit and no read timeout, so a stylesheet URL referencing an attacker-controlled host could be used to exhaust server memory. Upstream fixed this in the commit “Add a size limit to the CSS proxy content processing”, which caps the response at 5 MB, reads it as a stream and applies a read timeout.

Impact & exploitability

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

Affected products we track (1)

Recommendation

Apply the vendor fix in your normal patch cycle. Open any affected product above for its exact safe version.

Official patch: https://github.com/roundcube/roundcubemail/commit/2c9f6da692fa37cad2aaf85d5b127b583d22b264 ↗

Additional information

• NVD record
• https://github.com/roundcube/roundcubemail/commit/2c9f6da692fa37cad2aaf85d5b127b583d22b264Patch
• https://github.com/roundcube/roundcubemail/commit/99a5bdd05b01f45493cc0da4c96968eac7668126Patch
• https://bugs.debian.org/1151279Advisory
• https://github.com/roundcube/roundcubemail/releases/tag/1.6.20
• https://github.com/roundcube/roundcubemail/releases/tag/1.7.5
• https://roundcube.net/news/2026/10/19/security-updates-1.6.20-and-1.7.5