CVE-2026-127029: Memory Corruption (CVSS 7.5)

Description

A flaw was found in freeradius's Extensible Authentication Protocol Method for Subscriber Identity Module (EAP-SIM) module. When handling authentication requests, the server copies a client-supplied identity into an internal structure without properly checking its length against a fixed-size buffer. An unauthenticated remote attacker can exploit this issue by sending specially crafted EAP-SIM messages, triggering a stack buffer overflow that crashes the service and results in a Denial of Service (DoS).

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CVSS v3.1 Score

7.5

HIGH

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

Weakness Type (CWE)

CWE-787 Out-of-bounds Write

References

Other References

https://access.redhat.com/security/cve/CVE-2026-127029 https://bugzilla.redhat.com/show_bug.cgi?id=2572339 https://github.com/FreeRADIUS/freeradius-server/commit/064567a08f3b9d9b4863fab6060fafe296ac7de9 https://github.com/FreeRADIUS/freeradius-server/commit/e415f818dcdf91626e5e7314b3a4f819ab11f572

Frequently Asked Questions

What is CVE-2026-127029? +

A flaw was found in freeradius's Extensible Authentication Protocol Method for Subscriber Identity Module (EAP-SIM) module. When handling authentication requests, the server copies a client-supplied identity into an internal structure without properly checking its length against a fixed-size buffer. An unauthenticated remote attacker can exploit this issue by sending specially crafted EAP-SIM messages, triggering a stack buffer overflow that crashes the service and results in a Denial of Service (DoS). It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2026-127029? +

CVE-2026-127029 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

How do I check if I'm vulnerable to CVE-2026-127029? +

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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