Vulnerability · Published Apr 3, 2026 · Assigned by mitre
CVE-2026-35542
Medium 5.3
In plain English
A medium-severity security flaw 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 0.4% (higher than 36% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)5.3Medium
Exploit odds (30 days)0.4%top 63.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. The remote image blocking feature can be bypassed via a crafted background attribute of a BODY element in an e-mail message. This may lead to information disclosure or access-control bypass.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | roundcube | 1.6.5+dfsg-1+deb12u8 | DEBIAN-CVE-2026-35542 |
| Debian:13 | roundcube | 1.6.15+dfsg-0+deb13u1 | DEBIAN-CVE-2026-35542 |
| Debian:14 | roundcube | 1.6.14+dfsg-1 | DEBIAN-CVE-2026-35542 |
| Packagist | roundcube/roundcubemail | 1.7-rc5 | GHSA-5hf6-crg4-fg59 |
| Ubuntu:25.10 | roundcube | no fix listed | UBUNTU-CVE-2026-35542 |
| Ubuntu:26.10 | roundcube | no fix listed | UBUNTU-CVE-2026-35542 |
Affected products (as reported)
Weakness: CWE-669 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
References
- https://roundcube.net/news/2026/03/18/security-updates-1.7-rc5-1.6.14-1.5.14
- https://github.com/roundcube/roundcubemail/releases/tag/1.7-rc5
- https://github.com/roundcube/roundcubemail/commit/fd0e98178db5c73eaa93d005b561874923f9b0f0
- https://github.com/roundcube/roundcubemail/releases/tag/1.6.14
- https://github.com/roundcube/roundcubemail/commit/fde14d01adc9f37893cd82b635883e516ed453f8
- https://github.com/roundcube/roundcubemail/releases/tag/1.5.14
- https://github.com/roundcube/roundcubemail/commit/e052328e3dc75f13adc2e314eaa4096ac21084ad