CVE-2026-35539

EUVD-2026-18581
An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. XSS exists because of insufficient HTML attachment sanitization in preview mode. A victim must preview a text/html attachment.
Cross-site Scripting
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
6.1 MEDIUM
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 16.76%
Affected Products (NVD)
VendorProductVersion
roundcubewebmail
𝑥
< 1.5.14
roundcubewebmail
1.6.0 ≤
𝑥
< 1.6.14
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
roundcube
bookworm
1.6.5+dfsg-1+deb12u9
fixed
bookworm (security)
1.6.5+dfsg-1+deb12u10
fixed
bullseye
vulnerable
bullseye (security)
1.4.15+dfsg.1-1+deb11u10
fixed
forky
1.6.17+dfsg-1
fixed
sid
1.6.18+dfsg-1
fixed
trixie
1.6.16+dfsg-0+deb13u1
fixed
trixie (security)
1.6.17+dfsg-0+deb13u1
fixed
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
roundcube
bionic
needs-triage
focal
needs-triage
jammy
needs-triage
noble
needs-triage
questing
ignored
resolute
needs-triage
xenial
ignored
Common Weakness Enumeration
References
https://github.com/roundcube/roundcubemail/commit/10a6d1fa8acac85c727b0a6ae4a6642bfa27bea1
https://github.com/roundcube/roundcubemail/commit/1b30edf5369668c92fe91dae3d52e477c808aa4f
https://github.com/roundcube/roundcubemail/commit/d742954ccbcdee7020f8f2e7c49ce0fca5a0efab
https://github.com/roundcube/roundcubemail/releases/tag/1.5.14
https://github.com/roundcube/roundcubemail/releases/tag/1.6.14
https://github.com/roundcube/roundcubemail/releases/tag/1.7-rc5
https://roundcube.net/news/2026/03/18/security-updates-1.7-rc5-1.6.14-1.5.14