CVE-2026-114716 (CVSS 8.5)

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().

Is your site exposed to CVE-2026-114716?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

8.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:N

EPSS — Exploit Prediction

0.0039

Probability of exploitation

0.32%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-99 CWE-99

References

Other References

https://bugs.debian.org/1151279 https://github.com/roundcube/roundcubemail/commit/7f3cc9cacb16cb3ab047fe8e3cba81db2023cdfc https://github.com/roundcube/roundcubemail/commit/adb9b9b3fd43e30af1c166b79494726d89f828eb https://github.com/roundcube/roundcubemail/releases/tag/1.6.20 https://github.com/roundcube/roundcubemail/releases/tag/1.7.5 https://roundcube.net/news/2026/10/19/security-updates-1.6.20-and-1.7.5

Frequently Asked Questions

What is CVE-2026-114716? +

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(). It has a CVSS v3.1 base score of 8.5 (HIGH).

How severe is CVE-2026-114716? +

CVE-2026-114716 has a CVSS v3.1 score of 8.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0039, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-114716? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2025-43491 9.8

A vulnerability in the Poly Lens Desktop application running on the Windows platform might allow modifications to the filesystem, which …

CVE-2025-0756 9.1

Overview The product receives input from an upstream component, but it does not restrict or incorrectly restricts the input before …

CVE-2025-2410 9.1

Port manipulation vulnerabilities in ASPECT provide attackers with the ability to con-trol TCP/IP port access if session administrator credentials become …

CVE-2024-57971 9.1

DataSourceResource.java in the SpagoBI API support in Knowage Server in KNOWAGE before 8.1.30 does not ensure that java:comp/env/jdbc/ occurs at …

CVE-2024-5706 8.8

The product receives input from an upstream component, but it does not restrict or incorrectly restricts the input before it …

CVE-2026-50218 8.5

Akamai GPA (Guardicore Platform Agent) client on all platforms before 7.4 improperly validates JWT tokens used for seeding. By convincing …

CVE-2026-114716