CVSS 3.1
7.5 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVE-2026-127029 Freeradius: stack-based buffer overflow via unbounded eap-sim identity length
High (7.5) in red hat. EPSS 0.6% estimated probability of exploitation activity in the next 30 days.
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).
Severity
- EPSS
- 0.6% estimated probability of exploitation activity in the next 30 days; 49th percentile. Scored 2026-11-13. A forecast for this CVE across the internet, not for your own systems.
- CISA's assessment (SSVC)
- Exploitation: none · Automatable: yes · Technical impact: partial, assessed 2026-11-13. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
- CWE
- CWE-787 Out-of-bounds Write
- Published
- Modified
- Assigned by
- redhat (CNA)
- NVD analysis
- Awaiting analysis
- Record from
- the NVD, synced
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Affected
- red hat:red hat enterprise linux 10
- red hat:red hat enterprise linux 6
- red hat:red hat enterprise linux 7
- red hat:red hat enterprise linux 8
- red hat:red hat enterprise linux 9
Linux distributions
| Distribution | Release | Package | Fixed in | Advisory |
|---|---|---|---|---|
| Ubuntu | 18.04:LTS, 20.04:LTS, 22.04:LTS and 4 more | freeradius | no fix listed | UBUNTU-CVE-2026-127029 |
From the distributions' data via OSV.dev: Ubuntu Security Notices © Canonical Ltd., CC BY-SA 4.0. Modified: reformatted and linked to CVE records. Credits. On the distributions' own pages: Ubuntu.