Postorius is vulnerable to XSS
Date: 2026-05
Affected: pip/postorius
Attack vector: xss
Category: vulnerability-disclosure
Severity: High
CVE: CVE-2026-44742
CWE: CWE-79
CVSS: 7.2 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N)

Postorius through 1.3.13 does not escape HTML in the message subject when rendering it in the Held messages pop-up, as exploited in the wild in May 2026.


Mitigations:

Architectural layers (MAESTRO):