CVE-2026-73629

EUVD-2026-57798
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.
SSRF
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
VulnCheckCNA
8.5 HIGH
NETWORK
LOW
LOW
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
s9yserendipity
𝑥
< 2.6.0
CNA
Common Weakness Enumeration
References
https://github.com/s9y/Serendipity/security/advisories/GHSA-2m48-gjj5-5x86
https://www.vulncheck.com/advisories/serendipity-before-ssrf-via-hex-ipv4-and-ipv6-addresses