Cross-Origin Flaw in RESTEasy's CorsFilter Affects Web Applications
CVE-2026-89058

7.4HIGH

Key Information:

Vendor

Red Hat
Status
Vendor
CVE Published:
18 September 2026

What is CVE-2026-89058?

A security flaw exists in RESTEasy's CorsFilter, where setting the configuration to allow all origins ('*') permits it to reflect the Origin header in the Access-Control-Allow-Origin response. Coupled with Access-Control-Allow-Credentials set to true, this creates a dangerous scenario where a malicious website can execute credentialed cross-origin requests. As a result, sensitive data from authenticated sessions can be exposed, leading to confidentiality breaches that could severely impact users.

References

https://access.redhat.com/security/cve/CVE-2026-89058
vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2519775
issue-trackingx_refsource_REDHAT
https://github.com/resteasy/resteasy/security/advisories/...

CVSS V3.1

Score:
7.4
Severity:
HIGH
Confidentiality:
High
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Red Hat would like to thank Yu Bao (PayPal Cyber Security Team) for reporting this issue.
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