CVE-2026-33644CWE-918

Lychee has SSRF bypass via DNS rebinding — PhotoUrlRule only validates IP addresses, not hostnames resolving to internal IPs

Low · published March 26, 2026

CVSS v4.0
2.3
EPSS
0%
Percentile
23.3
In the wild
Unconfirmed
What it is

Lychee is a free, open-source photo-management tool. Prior to version 7.5.2, the SSRF protection in `PhotoUrlRule.php` can be bypassed using DNS rebinding. The IP validation check (line 86-89) only activates when the hostname is an IP address. When a domain name is used, `filter_var($host, FILTER_VALIDATE_IP)` returns `false`, skipping the entire check. Version 7.5.2 patches the issue.

The record
Technical detail
CVSS v4.0
2.3 · LOW
Vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N
EPSS
0.00316 · 23.3th percentile
Weakness
CWE-918 · Server-Side Request Forgery (SSRF)
Published
2026-03-26T20:04Z
EPSS history
Timeline
  • 26 MAR 20:04Z
    Lychee has SSRF bypass via DNS rebinding — PhotoUrlRule only validates IP addresses, not hostnames resolving to internal IPs
    cvelistv5