What is CVE-2026-67350?

CVE-2026-67350 is a medium-severity vulnerability in S9y Serendipity, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 4.3/10. Published 2026-07-31.

How severe is CVE-2026-67350?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Open Redirect in S9y Serendipity

CVE-2026-67350

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.

Vulnerability class: Open Redirect

EPSS: 0.003 (17.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N.

Affected products

S9y Serendipity — versions 0, 2.6.1

Weakness classification (CWE)

CWE-601 — URL Redirection to Untrusted Site (Open Redirect)

References

disclosure@vulncheck.com (vendor-advisory)
disclosure@vulncheck.com (third-party-advisory)

Frequently asked questions

What is CVE-2026-67350?: CVE-2026-67350 is a medium-severity vulnerability in S9y Serendipity, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 4.3/10. Published 2026-07-31.
How severe is CVE-2026-67350?: Medium severity. CVSS v3 base score is 4.3 out of 10.