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…

PriorityP431medium5.3CVSS 3.1

AVNACLPRNUINSUCNINAL

EPSS

0.43%

36.3th percentile

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.

Affected

2 ranges

Vendor	Product	Version range	Fixed in
roundcube	webmail	>= 1.6.0 < 1.6.20	1.6.20
roundcube	webmail	>= 1.7.0 < 1.7.5	1.7.5

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