CVE intelligence and bounded remediation
CVE-2026-42459 — free5GC is an open-source implementation of the 5G core network
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.
- Severity
- High
- CVSS
- 7.7 (4.0)
- Published
- 2026-05-27
- CISA KEV
- Not currently listed
- Ecosystem
- software/application
- Weaknesses
- CWE-20, CWE-209
Affected products
- free5gc / free5gc
Matched remediation archetype
Information disclosure and sensitive data exposure
This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.
Check exposure
- Trace sensitive data through responses, errors, logs, metrics, traces, caches, exports, files, backups, and client bundles.
- Identify affected subjects, tenants, retention windows, access controls, and downstream copies without opening unnecessary sensitive records.
- Review metadata, timing, status, length, and existence signals as well as direct content disclosure.
Remediate safely
- Minimize collection and output, apply field-level authorization and redaction at a centralized boundary, and return generic external errors.
- Remove secrets and sensitive data from logs, artifacts, URLs, caches, and client-side bundles; rotate credentials that may have been exposed.
- Update the affected component and add synthetic-data tests for response, error, observability, and export paths.
Authoritative sources
Complete CVE record and remediation plan
The detailed catalog view below loads this exact record, its source evidence, and the full seven-phase agentic change plan.