Vulnerability · Published Aug 17, 2026 · Assigned by mitre
CVE-2026-75004
Medium 4.3
In plain English
A medium-severity command injection 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 20% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)4.3Medium
Exploit odds (30 days)0.3%top 80.1% 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, improper rule name quoting could lead to managesieve_disabled_actions setting bypass via a crafted rule name in a Sieve script. This issue only affects Roundcube instances using the managesieve plugin.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | roundcube | 1.6.5+dfsg-1+deb12u11 | DEBIAN-CVE-2026-75004 |
| Debian:13 | roundcube | 1.6.18+dfsg-0+deb13u1 | DEBIAN-CVE-2026-75004 |
| Debian:14 | roundcube | 1.6.18+dfsg-1 | DEBIAN-CVE-2026-75004 |
| Ubuntu:26.10 | roundcube | no fix listed | UBUNTU-CVE-2026-75004 |
Affected products (as reported)
Weakness: CWE-77 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N