Server-Side Request Forgery (SSRF) in Roundcube Webmail - #VU162692
Published: November 9, 2026
Vulnerability identifier: #VU162692
CSH Severity: Low
CVSS v4: 4.6 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-918
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause server-side requests to destinations intended to be blocked.
The vulnerability exists due to incomplete destination validation in Roundcube Webmail's CSS proxy is_local_url() checks when processing URLs using nip.io or sslip.io hostnames. A remote attacker can supply a crafted URL using one of these domains to bypass the local-address filter and induce a server-side request to a restricted destination.
Affected software
Roundcube Webmail
Remediation
Install security update from vendor's website.
Roundcube Webmail - addressed in versions 1.6.21, 1.7.6