Vulnerability · Published Mar 26, 2026 · Assigned by GitHub_M

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

Low 2.3

In plain English

A low-severity server-side request forgery in Lychee from LycheeOrg. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 15% of all known vulnerabilities).

Severity (CVSS 4.0)2.3Low

Exploit odds (30 days)0.2%top 85.0% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
LycheeOrg	Lychee	< 7.5.2

Weakness: CWE-918 · 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

References

https://github.com/LycheeOrg/Lychee/security/advisories/GHSA-5245-4p8c-jwff x_refsource_CONFIRM
https://github.com/LycheeOrg/Lychee/commit/28c5261fb9deab4f9420c8cc2f73a87425939107 x_refsource_MISC