CVE-2026-33537
Lychee has SSRF bypass via incomplete IP validation in Photo::fromUrl — loopback and link-local IPs not blocked
Description
Lychee is a free, open-source photo-management tool. The patch introduced for GHSA-cpgw-wgf3-xc6v (SSRF via `Photo::fromUrl`) contains an incomplete IP validation check that fails to block loopback addresses and link-local addresses. Prior to version 7.5.1, an authenticated user can still reach internal services using direct IP addresses, bypassing all four protection configuration settings even when they are set to their secure defaults. Version 7.5.1 contains a fix for the issue.
INFO
Published Date :
March 26, 2026, 9:17 p.m.
Last Modified :
April 1, 2026, 6:56 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update Lychee to version 7.5.1 or later.
- Verify IP validation checks are correctly configured.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-33537.
| URL | Resource |
|---|---|
| https://github.com/LycheeOrg/Lychee/commit/41386677681d18cd04e42a35b50bd88bf53a4a6a | Patch |
| https://github.com/LycheeOrg/Lychee/security/advisories/GHSA-vq6w-prpf-h287 | Exploit Mitigation Patch Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-33537 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-33537
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-33537 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-33537 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Apr. 01, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N Added CPE Configuration OR *cpe:2.3:a:lycheeorg:lychee:*:*:*:*:*:*:*:* versions up to (excluding) 7.5.1 Added Reference Type GitHub, Inc.: https://github.com/LycheeOrg/Lychee/commit/41386677681d18cd04e42a35b50bd88bf53a4a6a Types: Patch Added Reference Type GitHub, Inc.: https://github.com/LycheeOrg/Lychee/security/advisories/GHSA-vq6w-prpf-h287 Types: Exploit, Mitigation, Patch, Vendor Advisory -
New CVE Received by [email protected]
Mar. 26, 2026
Action Type Old Value New Value Added Description Lychee is a free, open-source photo-management tool. The patch introduced for GHSA-cpgw-wgf3-xc6v (SSRF via `Photo::fromUrl`) contains an incomplete IP validation check that fails to block loopback addresses and link-local addresses. Prior to version 7.5.1, an authenticated user can still reach internal services using direct IP addresses, bypassing all four protection configuration settings even when they are set to their secure defaults. Version 7.5.1 contains a fix for the issue. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/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 Added CWE CWE-918 Added Reference https://github.com/LycheeOrg/Lychee/commit/41386677681d18cd04e42a35b50bd88bf53a4a6a Added Reference https://github.com/LycheeOrg/Lychee/security/advisories/GHSA-vq6w-prpf-h287