8.7

CVE-2026-33192: free5GC UDM incorrectly returns 500 for empty supi path parameter in PATCH sdm-subscriptions reques

Analyzed
AliasesUBUNTU-CVE-2026-33192GHSA-5rvc-5cwx-g5x8GO-2026-4755
Published 20-03-2026Last modified 20-03-2026

Vulnerability summary

CVE-2026-33192 is a high (CVSS 8.7) vulnerability in free5gc. EPSS estimates a 0.42% chance of exploitation in the next 30 days, higher than 34.8% of scored vulnerabilities. 1 public exploit is recorded.

Overall risk
45/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.7/10
010
High · v4.0 (CVE.org)
EPSS score
0.42%
0%100%
Low · +0.09 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits1github

Advisory lineage

Upstream 0 · Downstream 2 · Related 2
OPENSUSE-SU-2026:21483-1SUSE-SU-2026:1135-1

Timeline

  1. 20-03-2026
    PublishedVulnerability first disclosed.
  2. 20-03-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.42%

Chance of exploitation in the next 30 days

Percentile

35%

Versus all other CVEs

30-day change

Increase +0.09 pp

From 0.32% on 22-09-2026

22-09-202622-10-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

1 found
  • githubUnverified

    Free5Gc

    Maturity: poc

Weaknesses

CWE · root cause

Affected systems

Ubuntu157 products
  • linuxAll versions (No fix recorded)
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded)
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Free5gc2 products
Github.com/free5gc1 product
  • udm< 1.4.2

3 vendors · 160 products

References

7 links