THREAT OPS › Threat News › [GHSA] GHSA-qj55-47fp-p62j (medium) — free5GC AUSF: null byte injection in supiOrSuci causes HTTP 500 internal service failure
[GHSA] GHSA-qj55-47fp-p62j (medium) — free5GC AUSF: null byte injection in supiOrSuci causes HTTP 500 internal service failure
GHSA-qj55-47fp-p62j Severity: medium CVE: CVE-2026-53551
free5GC AUSF: null byte injection in supiOrSuci causes HTTP 500 internal service failure
### Summary
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
Indicators of compromise
- CVE-2026-53551cve
- http://%s/nudm-ueau/v1/%s/security-information/url
- 172.24.0.0/16cidr
- mnc093.mcc208.3gppnetwork.orgdomain
Original source: https://github.com/advisories/GHSA-qj55-47fp-p62j