CVE-2025-50864 elysia-cors Origin Validation Error
Attackers can bypass CORS restrictions in the elysia-cors library by using substring-matched origins, enabling unauthorized access to user data.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2025-50864?
CVE-2025-50864 is a medium-severity vulnerability in n/a, published on 20 Aug 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
An Origin Validation Error in the elysia-cors library thru 1.3.0 allows attackers to bypass Cross-Origin Resource Sharing (CORS) restrictions. The library incorrectly validates the supplied origin by checking if it is a substring of any domain in the site's CORS policy, rather than performing an exact match. For example, a malicious origin like "notexample.com", "example.common.net" is whitelisted when the site's CORS policy specifies "example.com." This vulnerability enables unauthorized access to user data on sites using the elysia-cors library for CORS validation.
Weakness: CWE-178
Which versions are affected by CVE-2025-50864?
2 open source packages ship an affected version, including @elysiajs/cors.
| Package | Affected | Fixed in |
|---|---|---|
@elysiajs/cors npm | All versions | 1.3.1 |
@elysiajs/cors npm | All versions | 1.3.1 |
How do I fix CVE-2025-50864?
Upgrade @elysiajs/cors to 1.3.1 or later.
Is CVE-2025-50864 being exploited?
There is no known exploitation of CVE-2025-50864 in the wild and no public exploit code.
Sources
Also known as GHSA-f9qj-4c5x-cpcw.