CVE-2026-73629
HighCVSS 8.5Exploitation Probability (EPSS)
Low risk9th percentile - higher than 9% of all known CVEs
Summary
Serendipity before 2.6.0 contains a server-side request forgery vulnerability in the serendipity_url_allowed() filter that fails to block hex-encoded IPv4 addresses, IPv6 literals, and link-local ranges. Authenticated users with adminImagesAdd permission can bypass the filter using alternate address formats to request internal services and retrieve response bodies through the public uploads directory.
Risk Assessment
An attacker could access internal network resources, potentially leading to disclosure of sensitive information or further attacks on the infrastructure.
Recommendation
Upgrade Serendipity to version 2.6.0 or later, which includes the fix.
Original NVD description (English source)
Serendipity before 2.6.0 contains a server-side request forgery vulnerability in the serendipity_url_allowed() filter that fails to block hex-encoded IPv4 addresses, IPv6 literals, and link-local ranges. Authenticated users with adminImagesAdd permission can bypass the filter using alternate address formats to request internal services and retrieve response bodies through the public uploads directory.