CVE-2026-33644 LOW

CVE-2026-33644: Lychee has SSRF bypass via DNS rebinding — PhotoUrlRule only validates IP addresses, not hostnames resolving to internal IPs

Vendor Lycheeorg
Product Lychee
Weakness CWE-918 · SSRF
Published March 26, 2026
Last update March 30, 2026
View on NVD All CVEs

CVSS base score

2.3/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality —
Integrity —

CVSS 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

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

March 26, 2026 CVE published
March 30, 2026 Record updated