Vulnerability in S9y Serendipity
CVE-2026-39963
Serendipity is a PHP-powered weblog engine. In versions 2.6-beta2 and below, the serendipity_setCookie() function in include/functions_config.inc.php uses $_SERVER['HTTP_HOST'] without validation as the domain parameter of setcookie(). An…
EPSS: 0.002 (13.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:L/A:N.
Affected products
- S9y Serendipity — versions 2.6.0, < 2.6.0
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Mitigation, Vendor Advisory)
- security-advisories@github.com (Product, x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-39963?
- CVE-2026-39963 is a medium-severity vulnerability in S9y Serendipity, classified under Reliance on Cookies without Validation and Integrity Checking. CVSS score: 6.9/10. Published 2026-04-15.
- How severe is CVE-2026-39963?
- Medium severity. CVSS v3 base score is 6.9 out of 10.