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.
Published: 2025-08-20
Score: 6.5 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
EUVD EUVD EUVD-2025-25313 elysia-cors Origin Validation Error
Github GHSA Github GHSA GHSA-f9qj-4c5x-cpcw elysia-cors Origin Validation Error
History

Mon, 26 Jan 2026 16:15:00 +0000


Thu, 21 Aug 2025 15:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-178
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 20 Aug 2025 15:00:00 +0000

Type Values Removed Values Added
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.
References

Subscriptions

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cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published:

Updated: 2026-01-26T16:01:04.029Z

Reserved: 2025-06-16T00:00:00.000Z

Link: CVE-2025-50864

cve-icon Vulnrichment

Updated: 2025-08-21T13:28:26.889Z

cve-icon NVD

Status : Deferred

Published: 2025-08-20T15:15:32.990

Modified: 2026-04-15T00:35:42.020

Link: CVE-2025-50864

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses