What is CVE-2026-33644?

CVE-2026-33644 is a medium-severity vulnerability in Lycheeorg Lychee, classified under Server-Side Request Forgery (SSRF). CVSS score: 4.3/10. Published 2026-03-26.

How severe is CVE-2026-33644?

Medium severity. CVSS v3 base score is 4.3 out of 10.

SSRF in Lycheeorg Lychee

CVE-2026-33644

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.

Vulnerability class: SSRF (Server-Side Request Forgery)

EPSS: 0.002 (12.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.

Affected products

Lycheeorg Lychee — versions < 7.5.2

Weakness classification (CWE)

CWE-918 — Server-Side Request Forgery (SSRF)

References

security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
security-advisories@github.com (Patch, x_refsource_MISC)

Frequently asked questions

What is CVE-2026-33644?: CVE-2026-33644 is a medium-severity vulnerability in Lycheeorg Lychee, classified under Server-Side Request Forgery (SSRF). CVSS score: 4.3/10. Published 2026-03-26.
How severe is CVE-2026-33644?: Medium severity. CVSS v3 base score is 4.3 out of 10.