CVE-2019-11049: Debian Linux

Critical severity, CVSS 9.8. EPSS: 4.2% chance of exploitation in the next 30 days.

In PHP versions 7.3.x below 7.3.13 and 7.4.0 on Windows, when supplying custom headers to mail() function, due to mistake introduced in commit 78f4b4a2dcf92ddbccea1bb95f8390a18ac3342e, if the header is supplied in lowercase, this can result in double-freeing certain memory locations.

Affected products

• Debian Debian Linux: version 10.0 only
• Fedoraproject Fedora: version 30 only; version 31 only
• PHP PHP: from 7.3.0, up to and including 7.3.13; version 7.4.0 only
• Tenable Security Center: before 5.19.0 (fixed in 5.19.0)

Published 2019-12-23. Last modified 2026-08-17.