Code Injection in Roundcube Webmail - #VU162686
Published: November 9, 2026
Vulnerability identifier: #VU162686
CSH Severity: Low
CVSS v4: 5.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-94
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to inject Sieve script instructions and alter mail-filter behavior.
The vulnerability exists due to insufficient neutralization of script syntax in Roundcube Webmail's Sieve rule operator handling when generating a Sieve script. A remote user can supply a crafted rule operator to introduce unintended Sieve instructions into the generated script.
Affected software
Roundcube Webmail
Remediation
Install security update from vendor's website.
Roundcube Webmail - addressed in versions 1.6.21, 1.7.6