Is CVE-2026-127030 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-127030 being exploited in the wild.

How severe is CVE-2026-127030?

High severity, with a CVSS score of 7.5, published 12 November 2026.

How is CVE-2026-127030 attacked?

It is attacked over the network, in a hosted service.

Am I affected by CVE-2026-127030?

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.

CVE-2026-127030: FreeRADIUS stack buffer overflow in EAP-FAST module

CVE-2026-127030 · Severity: high · CVSS 7.5 · Published 2026-11-12

FreeRADIUS is an open-source authentication server that handles network access credentials for enterprise systems. An improper length check in the optional EAP-FAST authentication method allows an attacker without credentials to crash the server by sending a malicious network request, causing the authentication service to become unavailable. This affects organizations that have explicitly enabled EAP-FAST, which is not the default configuration.

Technologies: Freeradius. Vendors: Freeradius.

Quick answers

Is CVE-2026-127030 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-127030 being exploited in the wild.
How severe is CVE-2026-127030?: 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-2026-127030?: No fixed version is recorded yet. Disable the EAP-FAST submodule by commenting out the `fast` section in `/etc/raddb/mods-available/eap` and ensuring `default_eap_type` is not set to `fast`, then restart the radiusd service. Alternatively, restrict UDP port 1812 to only trusted Network Access Server clients using firewall rules. 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-2026-127030 attacked?: It is attacked over the network, in a hosted service.
Am I affected by CVE-2026-127030?: 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-FAST submodule by commenting out the `fast` section in `/etc/raddb/mods-available/eap` and ensuring `default_eap_type` is not set to `fast`, then restart the radiusd service. Alternatively, restrict UDP port 1812 to only trusted Network Access Server clients using firewall rules.

Technical details

A stack-based buffer overflow exists in the EAP-FAST module due to insufficient validation of session ticket length during handshake processing. An unauthenticated remote attacker can send a specially crafted RADIUS packet to trigger the overflow and crash the server process, resulting in denial of service. The vulnerability is rated CWE-787 (out-of-bounds write) and requires network access but no authentication or user interaction.

Affected products

FreeRADIUS FreeRADIUS

Timeline

2026-11-12: disclosed

References

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