Resource exhaustion in Roundcube Webmail
CVE-2026-114731
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- bugs.debian.org/1151279 (issue-tracking, third-party-advisory)
- github.com/roundcube/roundcubemail/commit/2c9f6da692fa37cad2aaf85d5b127b583d22b… (patch)
- roundcube.net/news/2026/10/19/security-updates-1.6.20-and-1.7.5 (release-notes, vendor-advisory)
- github.com/roundcube/roundcubemail/releases/tag/1.7.5 (release-notes, patch)
- github.com/roundcube/roundcubemail/releases/tag/1.6.20 (release-notes, patch)
- github.com/roundcube/roundcubemail/commit/99a5bdd05b01f45493cc0da4c96968eac7668… (patch)
Frequently asked questions
- What is CVE-2026-114731?
- CVE-2026-114731 is a medium-severity vulnerability in Roundcube Webmail, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 5.3/10. Published 2026-10-22.
- How severe is CVE-2026-114731?
- Medium severity. CVSS v3 base score is 5.3 out of 10.