Vulnerability · Published Oct 22, 2026 · Assigned by mitre
CVE-2026-114716
High 8.5
In plain English
A high-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 38% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 is affected by a mail header injection vulnerability. rcmail_sendmail::extract_inline_images() used the media type taken from an inline image data URI without validating it, so a remote authenticated attacker could inject arbitrary MIME part headers into the outgoing message by placing CRLF sequences in that media type. Upstream fixed this in the commit “Fix mail header injection via media type in an inline image data URI”, which validates the media type with rcube_mime::is_mimetype_valid().
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | roundcube | no fix listed | DEBIAN-CVE-2026-114716 |
| Debian:13 | roundcube | 1.6.20+dfsg-0+deb13u1 | DEBIAN-CVE-2026-114716 |
| Debian:14 | roundcube | 1.6.20+dfsg-1 | DEBIAN-CVE-2026-114716 |
| Ubuntu:26.10 | roundcube | no fix listed | UBUNTU-CVE-2026-114716 |
Affected products (as reported)
Weakness: CWE-99 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:N
References
- https://bugs.debian.org/1151279 issue-tracking, third-party-advisory
- https://github.com/roundcube/roundcubemail/commit/7f3cc9cacb16cb3ab047fe8e3cba81db2023cdfc patch
- https://roundcube.net/news/2026/10/19/security-updates-1.6.20-and-1.7.5 vendor-advisory, release-notes
- https://github.com/roundcube/roundcubemail/releases/tag/1.7.5 release-notes, patch
- https://github.com/roundcube/roundcubemail/releases/tag/1.6.20 release-notes, patch
- https://github.com/roundcube/roundcubemail/commit/adb9b9b3fd43e30af1c166b79494726d89f828eb patch