Description
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.
References2
Metrics
- CVSS 3.1
-
8.5
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N - CVSS 4.0
-
8.4
HIGH
Score source: CNA
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:L/VA:N/SC:H/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 25 · as of 12 November 2026
- CWE
- CWE-918
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.