CVE-2026-48843 Server-side request forgery in Webmail
Insufficient CSS sanitization in Roundcube Webmail allows attackers to trigger SSRF or disclose information via malicious stylesheet links in HTML emails.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-48843?
CVE-2026-48843 is a high-severity server-side request forgery vulnerability in Roundcube Webmail, published on 25 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-918
Which versions are affected by CVE-2026-48843?
How do I fix CVE-2026-48843?
Upgrade to a fixed version.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-48843 being exploited?
There is no known exploitation of CVE-2026-48843 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-48843, GHSA-2hww-8583-w9wf, UBUNTU-CVE-2026-48843.