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Vulnerability record/PUBLISHED/Published Nov 12, 2026 16:21:48 UTC

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).

Base score7.5/ 10
SeverityHighCVSS 3.1

Exploitability / impact

CVSS metric breakdown

Vector-derived attributes
Base severityHigh
Attack vectorNetworkAV
Attack complexityLowAC
Privileges requiredNonePR
User interactionNoneUI
ScopeUnchangedS
Confidentiality impactNoneC
Integrity impactNoneI
Availability impactHighA
CVSS vector stringCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS communicates standardized severity and impact characteristics. It does not establish whether a system is exploitable in your specific environment.

Record context

CVE Numbering Authorityredhat
Last updatedNov 13, 2026 22:33:30 UTC
PublishedNov 12, 2026 16:21:48 UTC
ReservedNov 12, 2026 10:45:33 UTC

Credits

  • Red Hat would like to thank s4cr00t (Alipay Security Team) for reporting this issue. Upstream acknowledges Glen Saunders as the original reporter.