What’s Vulnerable › Vulnerabilities

CVE-2026-42459: free5GC: Improper Input Validation and Generation of Error Message Containing Sensitive Information in github.com/free5gc/udm

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-05-27 · updated 2026-10-14
• Weakness: CWE-20

Description

free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, the free5GC UDM component fails to validate the supi path parameter in six GET handlers of the nudm-sdm (Subscriber Data Management) service. An unauthenticated attacker can inject control characters into the SUPI parameter, causing UDM to forward a malformed request to UDR and return a 500 Internal Server Error response that exposes internal infrastructure details. This vulnerability is fixed in 4.2.2.

Affected products

• free5gc: before 4.2.2 — fixed in 4.2.2

How to fix

Upgrade to a fixed version: free5gc 4.2.2. Check the vendor advisory for mitigations.

References

• https://github.com/free5gc/free5gc/security/advisories/GHSA-585v-hcgf-jhfr
• https://github.com/free5gc/free5gc/security/advisories/GHSA-585v-hcgf-jhfr

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