Medium severity · published Apr 3, 2026
CVE-2026-35539
An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14
6.1
CVSS
0.3%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 16% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
WE
Webmail · Roundcube
before 1.5.14; 1.6.0 before 1.6.14 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-35539
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-35539
Patch
https://github.com/roundcube/roundcubemail/commit/10a6d1fa8acac85c727b0a6ae4a6642bfa27bea1
Patch
https://github.com/roundcube/roundcubemail/commit/1b30edf5369668c92fe91dae3d52e477c808aa4f
Patch
https://github.com/roundcube/roundcubemail/commit/d742954ccbcdee7020f8f2e7c49ce0fca5a0efab
Release Notes
https://github.com/roundcube/roundcubemail/releases/tag/1.5.14
Release Notes
https://github.com/roundcube/roundcubemail/releases/tag/1.6.14
Release Notes
https://github.com/roundcube/roundcubemail/releases/tag/1.7-rc5
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