CVE-2026-55785
LowCVSS 3.7Exploitation Probability (EPSS)
Low risk20th percentile - higher than 20% of all known CVEs
Summary
free5GC before version 1.4.5 has a vulnerability in the AUSF component where cryptographic comparisons (RES* and XRES*, AT_MAC and XMAC) are performed using ordinary equality helpers, and the expected XRES* value is logged at INFO level. This can expose authentication material to parties with access to AUSF logs.
Risk Assessment
The risk is leakage of sensitive authentication data into logs, which may allow unauthorized entities (operators, log collectors, processes) to read this data and potentially compromise authentication security.
Recommendation
It is recommended to immediately upgrade free5GC to version 1.4.5 or later, which includes a fix for this vulnerability.
Other vulnerabilities in free5GC
See all- CVE-2026-30073Unknown
A vulnerability in the NssaiAvailabilitySubscriptionCreate component of free5gc v4.0.1 allows an attacker to cause a Denial of Service (DoS) via a crafted POST request.
- CVE-2026-30072Unknown
A NULL pointer dereference in the CDR processing path of free5gc v4.0.1 allows attackers to cause a Denial of Service (DoS) by supplying a crafted payload.
- CVE-2026-30071Unknown
An issue in the RechargePut function of free5gc v4.0.1 allows attackers to cause a Denial of Service (DoS) via crafted input.
- CVE-2026-30070Unknown
An issue in the HandleGetSharedData function of free5gc v4.0.1 allows attackers to cause a Denial of Service (DoS) via crafted input.
- CVE-2026-30069Unknown
A NULL pointer dereference in the UDMC registration handler component of free5gc v4.0.1 allows attackers to cause a Denial of Service (DoS) by supplying a crafted payload.
- CVE-2026-30068Unknown
Improper input validation in the HandleUpdate function (/sbi/parameter_provision.go) of free5gc v4.0.1 allows attackers to cause a Denial of Service (DoS) via crafted input.
- CVE-2026-30067Unknown
An issue in the complexQueryFilterSubprocess function in the NRF Discovery service of free5gc v4.0.1 allows attackers to cause a Denial of Service (DoS) via crafted input.
- CVE-2026-30064Unknown
Improper input validation in the buildFilter function (processor/processor.go) of free5gc v4.0.1 allows attackers to cause a Denial of Service (DoS) via crafted input.
- CVE-2026-30063Unknown
An issue in the NF Discovery endpoint of free5gc v4.0.1 allows attackers to cause a Denial of Service (DoS) via a crafted snssais query.
- CVE-2026-30060Unknown
An issue in free5gc v4.0.1 allows attackers to cause a Denial of Service (DoS) when parsing crafted SUCI data during UE registration.
Original NVD description (English source)
free5GC is an open-source implementation of the 5G core network. Prior to 1.4.5, the AUSF component performs cryptographic authentication comparisons in internal/sbi/processor/ue_authentication.go with ordinary equality helpers. Auth5gAkaComfirmRequestProcedure compares RES* and XRES* with strings.EqualFold and logs the expected XRES* value at INFO level before comparison. EapAuthComfirmRequestProcedure compares AT_MAC and XMAC with bytes.Equal and evaluates XRES == RES with ordinary string equality. These comparisons can return at mismatch-dependent times, although testing did not demonstrate a practical remote timing oracle because of HTTP/SBI timing noise. The INFO log exposes authentication material to operators, log collectors, sidecars, or processes able to read AUSF logs. This issue is fixed in version 1.4.5.