CVE-2026-42459
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.32%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 4.0
- 7.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.32% probability · 25th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-20, CWE-209
- Affected
- free5gc/free5gc
- Source
- security-advisories@github.com
References
- https://github.com/free5gc/free5gc/security/advisories/GHSA-585v-hcgf-jhfrExploit, Mitigation, Vendor Advisory
- https://github.com/free5gc/free5gc/security/advisories/GHSA-585v-hcgf-jhfrExploit, Mitigation, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.