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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-53551 Detail

Description

free5GC is an open-source implementation of the 5G core network. Prior to 1.4.5, the free5GC AUSF (Authentication Server Function) does not validate the supiOrSuci field in UE authentication requests. Null bytes (\x00) and other control characters pass through JSON parsing unchanged and are forwarded to the UDM in an unescaped URL path. This causes Go's net/url.Parse() to fail, returning HTTP 500 "System failure" and leaking internal stack traces. An unauthenticated attacker can trigger this at scale causing denial of service for all subscribers attempting authentication through the affected AUSF. This vulnerability is fixed in 1.4.5.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

Nist CVSS score does not match with CNA score
CNA:  GitHub, Inc.
CVSS-B 6.9 MEDIUM
Vector:  CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://github.com/free5gc/ausf/commit/bfc4a10094dbacbd862baa4686829f3fcc06ce1e GitHub, Inc.
https://github.com/free5gc/ausf/pull/61 GitHub, Inc.
https://github.com/free5gc/ausf/releases/tag/v1.4.5 GitHub, Inc.
https://github.com/free5gc/free5gc/issues/1048 GitHub, Inc.
https://github.com/free5gc/free5gc/releases/tag/v4.2.2 GitHub, Inc.
https://github.com/free5gc/free5gc/security/advisories/GHSA-qj55-47fp-p62j GitHub, Inc.

Weakness Enumeration

CWE-ID CWE Name Source
CWE-20 Improper Input Validation GitHub, Inc.  

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-53551
NVD Published Date:
07/31/2026
NVD Last Modified:
07/31/2026
Source:
GitHub, Inc.