CVE-2026-33192: Github.com/free5gc/udm Free5GC UDM Incorrectly Returns 500 Vulnerability
HIGHCVE-2026-33192 is a HIGH free5gc udm incorrectly returns 500 vulnerability (CWE-209: Generation of Error Message Containing Sensitive Information) affecting Github.com/free5gc/udm libraries in the Go ecosystem. The issue involves free5gc udm incorrectly returns 500 for empty supi path parameter in patch sdm-subscriptions reques. Remediation is available by upgrading affected packages to version 1.4.2.
CVE-2026-33192 at a Glance
How to Fix CVE-2026-33192
To remediate this vulnerability, upgrade all affected Github.com/free5gc/udm dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
Upgrade github.com/free5gc/udm to 1.4.2Run the following command in your project directory to verify that all resolved dependencies use the patched release:
inspect dependencies for github.com/free5gc/udmHow to Check if You Are Affected
To determine whether your application is affected by CVE-2026-33192, inspect your project dependencies for Github.com/free5gc/udm:
inspect dependencies for github.com/free5gc/udmAnalyze the terminal output to locate any version of Github.com/free5gc/udm in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.4.2), your application is affected.
Note: Verify declared build manifests and deployed runtime container environments.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-209: Generation of Error Message Containing Sensitive Information, where the product generates an error message that includes sensitive information about its environment, users, or associated data. In Github.com/free5gc/udm, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2026-33192 Affected Github.com/free5gc/udm Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
github.com/free5gc/udm
|
Go |
< 1.4.2
|
1.4.2
|
References
Frequently Asked Questions
What is CVE-2026-33192?
Which Github.com/free5gc/udm versions are affected?
What version fixes CVE-2026-33192?
Is github.com/free5gc/udm affected?
What CWE is associated with CVE-2026-33192?
How can I check Go dependencies for CVE-2026-33192?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-5rvc-5cwx-g5x8",
"modified" : "2026-03-20T21:24:36Z",
"published" : "2026-03-18T20:11:27Z",
"aliases" : [ "CVE-2026-33192" ],
"summary" : "free5GC UDM incorrectly returns 500 for empty supi path parameter in PATCH sdm-subscriptions reques",
"details" : "**Impact** \nThis is an Improper Error Handling vulnerability with Information Exposure implications, combined with an HTTP Method Translation issue. \n- **Security Impact**: The UDM incorrectly converts a downstream 400 Bad Request (from UDR) into a 500 Internal Server Error when handling PATCH requests with an empty `supi` path parameter. Additionally, the UDM incorrectly translates the PATCH method to PUT when forwarding to UDR, indicating a deeper architectural issue. 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 PATCH request with an empty `supi` (e.g., double slashes `//` in URL path), the UDM forwards a PUT request to UDR with the malformed path, 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 PATCH operations and may indicate improper HTTP method handling. \n- **Affected Parties**: All deployments of free5GC v4.0.1 using the UDM Nudm_SDM service with PATCH 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 PATCH requests with empty path parameters before they reach UDM.",
"severity" : [ {
"type" : "CVSS_V4",
"score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/free5gc/udm"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "1.4.2"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/free5gc/free5gc/security/advisories/GHSA-5rvc-5cwx-g5x8"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-33192"
}, {
"type" : "WEB",
"url" : "https://github.com/free5gc/free5gc/issues/784"
}, {
"type" : "WEB",
"url" : "https://github.com/free5gc/udm/pull/79"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/free5gc/udm"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-209" ],
"severity" : "HIGH",
"github_reviewed" : true,
"github_reviewed_at" : "2026-03-18T20:11:27Z",
"nvd_published_at" : "2026-03-20T09:16:16Z"
}
}