Quick answers
- Is CVE-2026-127029 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-127029 being exploited in the wild.
- How severe is CVE-2026-127029?
- High severity, with a CVSS score of 7.5, published 12 November 2026.
- Which products and versions are affected?
- FreeRADIUS FreeRADIUS.
- Is there a fix for CVE-2026-127029?
- No fixed version is recorded yet. Disable the EAP-SIM submodule by commenting out or removing the sim configuration block in /etc/raddb/mods-available/eap (or /etc/raddb/mods-enabled/eap) if SIM-based authentication is not required, then restart the RADIUS service. Additionally, restrict RADIUS UDP traffic (ports 1812 and 1813) to trusted Network Access Server IP addresses using firewall rules.</anigation> <parameter name="timeline">[{"kind":"disclosed","at":"2026-11-12"}] If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-127029 attacked?
- It is attacked over the network, in a hosted service.
- Am I affected by CVE-2026-127029?
- Check whether you run Freeradius. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
Disable the EAP-SIM submodule by commenting out or removing the sim configuration block in /etc/raddb/mods-available/eap (or /etc/raddb/mods-enabled/eap) if SIM-based authentication is not required, then restart the RADIUS service. Additionally, restrict RADIUS UDP traffic (ports 1812 and 1813) to trusted Network Access Server IP addresses using firewall rules.</anigation> <parameter name="timeline">[{"kind":"disclosed","at":"2026-11-12"}]
Technical details
A stack buffer overflow exists in FreeRADIUS's EAP-SIM module due to unbounded copying of client-supplied identity data into a fixed-size buffer. An unauthenticated remote attacker can exploit this via crafted EAP-SIM authentication messages over the network, triggering a crash that denies service to legitimate users. The vulnerability is only present if the EAP-SIM submodule is explicitly enabled in the FreeRADIUS configuration.
Affected products
- FreeRADIUS FreeRADIUS