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Vulnerability record · CVE-2026-42459 · published 27 May 2026

CVE-2026-42459: Free5gc improper input validation vulnerability

Free5gc · Free5gc

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.

7.7 CVSS 4.0 High EPSS 0.45% · top 63.6% CWE-20 · Improper input validationCWE-209 · Error message information leak
7.7CVSS 4.0 base score
0.45%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References, 2 tagged exploit
17 Jun 2026Last modified by NVD

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/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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

10.0CVE-2026-44327Free5gc missing authentication for critical function vulnerabilityfree5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's NEF mounts the nnef-oam route group without inbound OAuth2…EPSS 0.53%10.0CVE-2026-44329Free5gc missing authentication for critical function vulnerabilityfree5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's SMF mounts the UPI management route group without OAuth2/b…EPSS 0.56%10.0CVE-2026-44330Free5gc incorrect authorization vulnerabilityfree5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's NEF mounts the nnef-pfdmanagement route group without inbo…EPSS 0.43%9.8CVE-2023-4659Free5gc cross-site request forgery vulnerabilityCross-Site Request Forgery vulnerability, whose exploitation could allow an attacker to perform different actions on the platform as an administrator…EPSS 0.43%9.4CVE-2026-44326Free5gc missing authorization vulnerabilityfree5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's NEF mounts the 3gpp-traffic-influence API without inbound …EPSS 0.53%9.4CVE-2026-44315Free5gc missing authorization vulnerabilityfree5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's NEF mounts the 3gpp-pfd-management API without inbound OAu…EPSS 0.53%8.7CVE-2026-40246Free5gc improper authorization vulnerabilityfree5GC is an open-source implementation of the 5G core network. In versions 1.4.2 and below of the UDR service, the handler for deleting Traffic Inf…EPSS 0.45%8.7CVE-2026-40247Free5gc improper authorization vulnerabilityfree5GC is an open-source implementation of the 5G core network. In versions 4.2.1 and below of the UDR service, the handler for reading Traffic Infl…EPSS 0.51%

Source: NIST National Vulnerability Database (record CVE-2026-42459), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.