XSS in Roundcube Webmail
CVE-2026-74999
In Roundcube Webmail before 1.6.18 and 1.7.x before 1.7.3, the "Add to address book" action was subject to stored XSS.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (21.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 21st percentile — 21.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001
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/32f20c6bfd12dff9cfb6880ae303e740f0804… (Patch)
- github.com/roundcube/roundcubemail/releases/tag/1.7.3 (Release Notes)
- github.com/roundcube/roundcubemail/commit/2d2a9604a820ee279c9ffcfe856b9b93a9399… (Patch)
Frequently asked questions
- What is CVE-2026-74999?
- CVE-2026-74999 is a medium-severity vulnerability in Roundcube Webmail, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-08-17.
- How severe is CVE-2026-74999?
- Medium severity. CVSS v3 base score is 5.4 out of 10.