# CVE-2026-35540

## Summary

- **CVE ID:** CVE-2026-35540
- **Severity:** MEDIUM
- **CVSS Score:** 5.4 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N)
- **CWE:** CWE-669
- **Published:** Apr 3, 2026
- **Last Modified:** Apr 3, 2026

## 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 Products

- Roundcube — Webmail (1.6.0)

## References

- [CNA](https://roundcube.net/news/2026/03/18/security-updates-1.7-rc5-1.6.14-1.5.14)
- [CNA](https://github.com/roundcube/roundcubemail/releases/tag/1.7-rc5)
- [CNA](https://github.com/roundcube/roundcubemail/commit/579b68eff90650a5c782e153debd66c765648942)
- [CNA](https://github.com/roundcube/roundcubemail/releases/tag/1.6.14)
- [CNA](https://github.com/roundcube/roundcubemail/commit/27ec6cc9cb25e1ef8b4d4ef39ce76d619caa6870)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.39%
- **EPSS Percentile:** 32.0

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-12._