{"id":"CVE-2026-33065","aliases":["GHSA-958m-gxmc-mccm","GO-2026-4758"],"url":"https://o3.security/vulnerability/CVE-2026-33065","summary":"free5GC UDM incorrectly returns 500 for empty supi path parameter in DELETE sdm-subscriptions request","details":"**Impact**  \nThis is an Improper Error Handling  vulnerability with Information Exposure implications.  \n- **Security Impact**: The UDM incorrectly converts a downstream 400 Bad Request (from UDR) into a 500 Internal Server Error when handling DELETE requests with an empty `supi` path parameter. This leaks internal error handling behavior and makes it difficult for clients to distinguish between client-side errors and server-side failures.  \n- **Functional Impact**: When a client sends a DELETE request with an empty `supi` (e.g., double slashes `//` in URL path), the UDM forwards the malformed request to UDR, which correctly returns 400. However, UDM propagates this as 500 SYSTEM_FAILURE instead of returning the appropriate 400 error to the client. This violates REST API best practices for DELETE operations.  \n- **Affected Parties**: All deployments of free5GC v4.0.1 using the UDM Nudm_SDM service with DELETE operations on sdm-subscriptions endpoint.\n\n**Patches**  \nYes, the issue has been patched.  \nThe fix is implemented in PR free5gc/udm#79.  \nUsers should upgrade to the next release of free5GC that includes this commit.\n\n**Workarounds**  \nThere is no direct workaround at the application level. The recommendation is to apply the provided patch or implement API gateway-level validation to reject DELETE requests with empty path parameters before they reach UDM.","published":"2026-03-20T08:03:39.357Z","modified":"2026-10-28T02:31:12.580253387Z","cvss":null,"epss":{"score":0.00282,"percentile":0.2018,"asOf":"2026-08-24"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/free5gc/udm","fixedVersion":"1.4.2"}],"fix":{"url":"https://github.com/free5gc/udm/commit/88de9fa74a1b3f3522e53b4cfa2d184712ffa4ee","label":"free5gc/udm@88de9fa"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33065.json"},{"type":"ADVISORY","url":"https://github.com/free5gc/free5gc/security/advisories/GHSA-958m-gxmc-mccm"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-33065"},{"type":"REPORT","url":"https://github.com/free5gc/free5gc/issues/783"},{"type":"FIX","url":"https://github.com/free5gc/udm/commit/88de9fa74a1b3f3522e53b4cfa2d184712ffa4ee"},{"type":"FIX","url":"https://github.com/free5gc/udm/pull/79"},{"type":"PACKAGE","url":"https://github.com/free5gc/free5gc"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-28T02:31:12.580253387Z"}}