Vulnerability · Published Aug 17, 2026 · Assigned by mitre
CVE-2026-74999
Medium 5.4
In plain English
A medium-severity cross-site scripting in Webmail from Roundcube. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 18% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)5.4Medium
Exploit odds (30 days)0.3%top 82.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | roundcube | 1.6.5+dfsg-1+deb12u11 | DEBIAN-CVE-2026-74999 |
| Debian:13 | roundcube | 1.6.18+dfsg-0+deb13u1 | DEBIAN-CVE-2026-74999 |
| Debian:14 | roundcube | 1.6.18+dfsg-1 | DEBIAN-CVE-2026-74999 |
| Ubuntu:26.10 | roundcube | no fix listed | UBUNTU-CVE-2026-74999 |
Affected products (as reported)
Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
References
- https://roundcube.net/news/2026/08/09/security-updates-1.6.18-and-1.7.3
- https://github.com/roundcube/roundcubemail/releases/tag/1.6.18
- https://github.com/roundcube/roundcubemail/commit/32f20c6bfd12dff9cfb6880ae303e740f0804fe8
- https://github.com/roundcube/roundcubemail/releases/tag/1.7.3
- https://github.com/roundcube/roundcubemail/commit/2d2a9604a820ee279c9ffcfe856b9b93a93995a8