CVE-2026-35540
Low
No strong exploitation signal.
CVSS base
5.4
MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
EPSS — probability of exploitation (30 days)
0.4%
34.1th percentile
CISA KEV
Not listed
Weakness / dates
CWE-669
Published 2026-04-03 · modified 2026-07-24
CVSS breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
| Attack Vector | N | Network |
| Attack Complexity | H | High |
| Privileges Required | N | None |
| User Interaction | N | None |
| 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 1.6.0 before 1.6.14. Insufficient Cascading Style Sheets (CSS) sanitization in HTML e-mail messages may lead to SSRF or Information Disclosure, e.g., if stylesheet links point to local network hosts.
Affected
References
- https://github.com/roundcube/roundcubemail/commit/27ec6cc9cb25e1ef8b4d4ef39ce76d619caa6870
- https://github.com/roundcube/roundcubemail/commit/579b68eff90650a5c782e153debd66c765648942
- 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