CVE-2026-33192

free5GC UDM incorrectly returns 500 for empty supi path parameter in PATCH sdm-subscriptions reques

MEDIUM
5.3
CVSS Score
Published: March 20, 2026 at 08:09 AM UTC
Updated: June 17, 2026 at 10:37 AM UTC
2 products affected across 1 vendorUdmFREE5GC

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Severity
MEDIUM5.3
Exploit prediction
EPSS 0.3%
SSVC
PoC

Description

Free5GC is an open-source Linux Foundation project for 5th generation (5G) mobile core networks. In versions prior to 1.4.2, 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, making it difficult for clients to distinguish between client-side errors and server-side failures. The issue has been patched in version 1.4.2.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.4.2
v < 1.4.2
Affected range stops below 1.4.2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (3)

x_refsource_CONFIRMPatchVendor Advisory
Source: cverecord
https://github.com/free5gc/free5gc/security/advisories/GHSA-5rvc-5cwx-g5x8
x_refsource_MISCExploitIssue TrackingPatchVendor Advisory
Source: cverecord
https://github.com/free5gc/free5gc/issues/784
x_refsource_MISCIssue TrackingPatch
Source: cverecord
https://github.com/free5gc/udm/pull/79

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-209

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