Vulnerability · Published Mar 17, 2026 · Assigned by TYPO3

CVE-2026-1323Insecure Deserialization in extension "Mailqueue" (mailqueue)

Medium 5.2

In plain English

A medium-severity unsafe deserialization in Extension "Mailqueue" from TYPO3. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 14% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)5.2Medium

Exploit odds (30 days)0.2%top 86.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

The extension fails to properly define allowed classes used when deserializing transport failure metadata. An attacker may exploit this to execute untrusted serialized code. Note that an active exploit requires write access to the directory configured at $GLOBALS['TYPO3_CONF_VARS']['MAIL']['transport_spool_filepath'].

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Packagist	cpsit/typo3-mailqueue	0.4.5	GHSA-2pm6-9fhx-vvg3
Packagist	cpsit/typo3-mailqueue	0.5.2	GHSA-2pm6-9fhx-vvg3

Affected products (as reported)

Vendor	Product	Versions
TYPO3	Extension "Mailqueue"	0 – before 0.4.50.5.0 – before 0.5.2

Weakness: CWE-502 · Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:N/SC:H/SI:H/SA:H

References

https://typo3.org/security/advisory/typo3-ext-sa-2026-005 vendor-advisory