Vulnerability · Published Oct 22, 2026 · Assigned by mitre

CVE-2026-114728

Medium 5.3

In plain English

A medium-severity security flaw in Webmail from Roundcube. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 32% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.3Medium

Exploit odds (30 days)0.4%top 68.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 is affected by a remote content blocking bypass in the handling of FuncIRI attributes. rcube_washtml detected the CSS url() token with a pattern that enumerated only some of its escaped spellings, so values using other CSS escape sequences, for example \000075rl( or u\72 l(, were not recognized and remote content was loaded from an HTML message without the user's consent. Upstream fixed this in the commit “Fix remote content blocking bypass via CSS escapes in FuncIRI attributes (again)”, which resolves CSS escapes before matching and also inspects the `to`, `from` and `by` attributes.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	roundcube	no fix listed	DEBIAN-CVE-2026-114728
Debian:13	roundcube	1.6.20+dfsg-0+deb13u1	DEBIAN-CVE-2026-114728
Debian:14	roundcube	1.6.20+dfsg-1	DEBIAN-CVE-2026-114728
Ubuntu:26.10	roundcube	no fix listed	UBUNTU-CVE-2026-114728

Affected products (as reported)

Vendor	Product	Versions
Roundcube	Webmail	1.6.0 – before 1.6.201.7.0 – before 1.7.5

Weakness: CWE-184 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

References

https://bugs.debian.org/1151279 issue-tracking, third-party-advisory
https://github.com/roundcube/roundcubemail/commit/2f74267f0e13bed7182b1d2294cc4f3c5c46dcee patch
https://roundcube.net/news/2026/10/19/security-updates-1.6.20-and-1.7.5 vendor-advisory, release-notes
https://github.com/roundcube/roundcubemail/releases/tag/1.7.5 release-notes, patch
https://github.com/roundcube/roundcubemail/releases/tag/1.6.20 release-notes, patch
https://github.com/roundcube/roundcubemail/commit/ff4fcfdd2952f9d09947cc9c18137f381f27caf1 patch