CVE-2026-39971

Sažetak

Serendipity is a PHP-powered weblog engine. In versions 2.6-beta2 and below, the email sending functionality in include/functions.inc.php inserts $_SERVER['HTTP_HOST'] directly into the Message-ID SMTP header without validation, and the existing sanitization function serendipity_isResponseClean() is not called on HTTP_HOST before embedding it. An attacker who can control the Host header during an email-triggering action such as comment notifications or subscription emails can inject arbitrary SMTP headers into outgoing emails. This enables identity spoofing, reply hijacking via manipulated Message-ID threading, and email reputation abuse through the attacker's domain being embedded in legitimate mail headers. This issue has been fixed in version 2.6.0.

Reference

CVSS

Base:	7.2
Impact:	2.7
Exploitability:	3.9

Pristup

Vektor	Složenost	Autentikacija
NETWORK	LOW	NONE

Impact

Povjerljivost	Cjelovitost	Dostupnost
LOW	LOW	NONE

CVSS vektor

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

Zadnje važnije ažuriranje

17-04-2026 - 15:38

Objavljeno

15-04-2026 - 04:17