{"id":"CVE-2026-27642","summary":"free5GC has Improper Input Validation in UDM UEAU Service","details":"free5gc UDM provides Unified Data Management (UDM) for free5GC, an open-source project for 5th generation (5G) mobile core networks. In versions up to and including 1.4.1, remote attackers can inject control characters (e.g., %00) into the supi parameter, triggering internal URL parsing errors (net/url: invalid control character). This exposes system-level error details and can be used for service fingerprinting. All deployments of free5GC using the UDM Nudm_UEAU service may be affected. free5gc/udm pull request 75 contains a fix for the issue. No direct workaround is available at the application level. Applying the official patch is recommended.","aliases":["GHSA-h4wg-rp7m-8xx4"],"modified":"2026-08-12T03:51:17.452586027Z","published":"2026-02-24T00:18:56.360Z","database_specific":{"cwe_ids":["CWE-20"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27642.json","cna_assigner":"GitHub_M"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27642.json"},{"type":"ADVISORY","url":"https://github.com/free5gc/free5gc/security/advisories/GHSA-h4wg-rp7m-8xx4"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-27642"},{"type":"REPORT","url":"https://github.com/free5gc/free5gc/issues/749"},{"type":"FIX","url":"https://github.com/free5gc/udm/commit/a7af2321ddea6368c43835f90f6d1b9d67dd2ea1"},{"type":"FIX","url":"https://github.com/free5gc/udm/pull/75"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/free5gc/udm","events":[{"introduced":"0"},{"fixed":"a7af2321ddea6368c43835f90f6d1b9d67dd2ea1"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"last_affected":"1.4.1"}],"source":["CPE_RANGE","REFERENCES"],"cpe":"cpe:2.3:a:free5gc:udm:*:*:*:*:*:go:*:*"}}],"versions":["v1.4.1","v1.4.0","v1.3.2","v1.3.1","v1.3.0","v1.2.5","v1.2.4","v1.2.3","v1.2.2","v1.2.1","v1.2.0","v1.1.1","v1.1.0","v1.0.2","v1.0.1","v1.0.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-27642.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"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:U"}]}