Medium severity · published Aug 17, 2026
CVE-2026-75004
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…
4.3
CVSS
0.4%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 31% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
WE
Webmail · Roundcube
1.6.0 before 1.6.18; 1.7.0 before 1.7.3 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-75004
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-75004
Release Notes
https://github.com/roundcube/roundcubemail/releases/tag/1.6.18
Release Notes
https://github.com/roundcube/roundcubemail/releases/tag/1.7.3
Vendor Advisory
https://roundcube.net/news/2026/08/09/security-updates-1.6.18-and-1.7.3
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