CVE-2026-89058 (CVSS 7.4)

Description

A flaw was found in RESTEasy's CorsFilter, which, when configured to allow all origins ("*"), reflects the request's Origin header back in the Access-Control-Allow-Origin response together with Access-Control-Allow-Credentials: true. This permissive cross-origin policy allows a malicious website to make credentialed cross-origin requests and read authenticated responses from a victim's session, resulting in a loss of confidentiality.

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CVSS v3.1 Score

7.4

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N

EPSS — Exploit Prediction

0.0023

Probability of exploitation

0.12%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-942 CWE-942

References

Other References

https://access.redhat.com/security/cve/CVE-2026-89058 https://bugzilla.redhat.com/show_bug.cgi?id=2519775 https://github.com/resteasy/resteasy/commit/efeb2b7 https://github.com/resteasy/resteasy/security/advisories/GHSA-972r-f3fv-whm3 https://github.com/resteasy/resteasy/security/advisories/GHSA-972r-f3fv-whm3

Frequently Asked Questions

What is CVE-2026-89058? +

A flaw was found in RESTEasy's CorsFilter, which, when configured to allow all origins ("*"), reflects the request's Origin header back in the Access-Control-Allow-Origin response together with Access-Control-Allow-Credentials: true. This permissive cross-origin policy allows a malicious website to make credentialed cross-origin requests and read authenticated responses from a victim's session, resulting in a loss of confidentiality. It has a CVSS v3.1 base score of 7.4 (HIGH).

How severe is CVE-2026-89058? +

CVE-2026-89058 has a CVSS v3.1 score of 7.4 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0023, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-89058? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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