CVE-2026-35539
Low
No strong exploitation signal.
CVSS base
6.1
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS — probability of exploitation (30 days)
0.4%
26.5th percentile
CISA KEV
Not listed
Weakness / dates
CWE-79
Published 2026-04-03 · modified 2026-07-24
CVSS breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
| Attack Vector | N | Network |
| Attack Complexity | L | Low |
| Privileges Required | N | None |
| User Interaction | R | Required |
| Scope | C | Changed |
| Confidentiality | L | Low |
| Integrity | L | Low |
| Availability | N | None |
Timeline
- 2026-04-03 — Published (NVD)
- 2026-07-24 — Last modified (NVD)
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.
Affected
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