CVE-2026-75003: Roundcube Webmail · Incorrect Resource Transfer Between Spheres
Affects Roundcube WebmailSource CVE Database V5
Not known to be exploited · CVSS 5.8 Medium : upgrade to 1.7.3 or 1.6.18 when convenient.
Data as of 26 Oct 2026, 10:12 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 47% 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 can reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-08-17.
- Patch
- Available – fixed in 1.7.3, 1.6.18
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/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
Upgrade Roundcube Webmail to version 1.6.18 or later in the 1.6.x series, or 1.7.3 or later in the 1.7.x series, where this vulnerability has been fixed. No additional mitigation steps are indicated by the vendor advisory.
Description
CVE-2026-75003 affects Roundcube Webmail versions prior to 1.6.18 and 1.7.3. The vulnerability involves an unclosed url() in a FuncIRI attribute within an SVG image, which can bypass remote image blocking. This flaw may allow information disclosure or privilege escalation. The issue is fixed in versions 1.6.18 and 1.7.3.
References
- roundcube.net/news/2026/08/09/security-updates-1.6.18-and-1.7.3 (opens in a new tab)
- github.com/roundcube/roundcubemail/releases/tag/1.6.18 (opens in a new tab)
- github.com/roundcube/roundcubemail/commit/1cebea03474305d9f75a9a33d30880d290b5591b (opens in a new tab)
- github.com/roundcube/roundcubemail/releases/tag/1.7.3 (opens in a new tab)
- github.com/roundcube/roundcubemail/commit/440277c32e6d84f3d116153af1cc8454361a8a56 (opens in a new tab)