medium5.4
CVE-2026-35540
Roundcube Webmail: Insufficient CSS sanitization in HTML e-mail messages
Impact
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 packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| composer | roundcube/roundcubemail | >= 1.7-beta, < 1.7-rc5 | 1.7-rc5 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Roundcube | Webmail | from 1.6.0 before 1.6.14 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-vxg2-hhgr-37fx
- https://nvd.nist.gov/vuln/detail/CVE-2026-35540
- 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