CVE-2026-75004: Roundcube Webmail · Command Injection
Affects Roundcube WebmailSource CVE Database V5
Not known to be exploited · CVSS 4.3 Medium : upgrade to 1.7.3 or 1.6.18 when convenient.
Data as of 26 Oct 2026, 10:12 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 31% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-08-17.
- Patch
- Available – fixed in 1.7.3, 1.6.18
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 17 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade Roundcube Webmail to 1.7.3 or 1.6.18.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| RoundcubeWebmail | Affected
| Fixed in
|
| RoundcubeWebmail | Affected
| Fixed in
|
AI-suggested
Users should upgrade Roundcube Webmail to version 1.6.18 or later, or 1.7.3 or later, where this vulnerability is fixed. No other mitigation or workaround is indicated.
Description
CVE-2026-75004 is a command injection vulnerability in Roundcube Webmail versions before 1.6.18 and 1.7.x before 1.7.3. It arises from improper quoting of rule names in the managesieve plugin, allowing bypass of the managesieve_disabled_actions setting via crafted Sieve script rule names. This issue affects only Roundcube instances using the managesieve plugin.