Description
In Roundcube Webmail before 1.6.18 and 1.7.x before 1.7.3, the cmd_learn driver of the markasjunk plugin is subject to remote code execution via crafted placeholder replacement values. This issue only affects Roundcube instances using the markasjunk plugin with its cmd_learn driver.
Affected products
roundcube: webmail
References6
- roundcube.net/news/2026/08/09/security-updates-1.6.18-and-1.7.3 Vendor Advisory
- github.com/roundcube/roundcubemail/commit/14044f843cfacbe78b042… Patch
- github.com/roundcube/roundcubemail/commit/495d211638f222336b20f… Patch
- github.com/roundcube/roundcubemail/commit/b8f90e28a46d42e79a695… Patch
- github.com/roundcube/roundcubemail/releases/tag/1.6.18 Release Notes
- github.com/roundcube/roundcubemail/releases/tag/1.7.3 Release Notes
Metrics
- CVSS 3.1
-
8.8
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 1% percentile: 56 · as of 11 November 2026
- CWE
- CWE-78
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.