Vulnerability · Published Jul 31, 2026 · Assigned by VulnCheck

CVE-2026-67350Serendipity < 2.6.1 Open Redirect via exit.php

Medium 4.3

In plain English

A medium-severity open redirect in Serendipity from s9y. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 29% of all known vulnerabilities).

Severity (CVSS 3.1)4.3Medium

Exploit odds (30 days)0.3%top 71.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

Serendipity before 2.6.1 contains an open redirect vulnerability in exit.php that allows unauthenticated attackers to redirect users to arbitrary external sites by supplying a malicious Base64-encoded url parameter when the Track Exits plugin is configured with commentredirection set to s9y. Attackers can craft trusted-looking URLs leveraging the legitimate blog domain to conduct phishing, deliver malware, or bypass URL reputation filters.

Affected products (as reported)

Vendor	Product	Versions
s9y	Serendipity	0 – before 2.6.1

Weakness: CWE-601 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

References

GitHub Security Advisory (GHSA-77rw-27c5-4hxm) vendor-advisory
https://www.vulncheck.com/advisories/serendipity-open-redirect-via-exit-php third-party-advisory