RCE in Roundcube Webmail
CVE-2026-74997
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.
Vulnerability class: Command Injection (OS Command Injection)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.011 (65.3th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 65th percentile — 65.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.008 · newest: 0.011 · change: +0.004
Affected products
- Roundcube Webmail — versions 1.6.0, 1.7.0
Weakness classification (CWE)
References
- roundcube.net/news/2026/08/09/security-updates-1.6.18-and-1.7.3 (Vendor Advisory)
- github.com/roundcube/roundcubemail/releases/tag/1.6.18 (Release Notes)
- github.com/roundcube/roundcubemail/commit/b8f90e28a46d42e79a69568cba897f8f4223d… (Patch)
- github.com/roundcube/roundcubemail/commit/495d211638f222336b20f4744545c53712426… (Patch)
- github.com/roundcube/roundcubemail/releases/tag/1.7.3 (Release Notes)
- github.com/roundcube/roundcubemail/commit/14044f843cfacbe78b042f659e379d6b4497a… (Patch)
Frequently asked questions
- What is CVE-2026-74997?
- CVE-2026-74997 is a high-severity vulnerability in Roundcube Webmail, classified under OS Command Injection. CVSS score: 8.8/10. Published 2026-08-17.
- How severe is CVE-2026-74997?
- High severity. CVSS v3 base score is 8.8 out of 10.