CVE-2026-44329Public exploitNetwork attack vector

Unauthenticated topology access via unprotected UPI routes

Published May 27, 2026 · Updated May 27, 2026

Authentication bypass in free5GC before 4.2.2 allows remote attackers to read, write, and delete SMF user-plane topology data. The SMF newRouter function mounts the UPI route group without the OAuth2 bearer-token check applied to the sibling OAM group. SBI reachability alone exposes topology-management handlers, permitting anonymous topology disclosure and modification that can disrupt UPF selection and sessions.

CVSS severity10.0
Critical
EPSS probability0.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in free5GC before 4.2.2 allows remote attackers to read, write, and delete SMF user-plane topology data. The SMF newRouter function mounts the UPI route group without the OAuth2 bearer-token check applied to the sibling OAM group. SBI reachability alone exposes topology-management handlers, permitting anonymous topology disclosure and modification that can disrupt UPF selection and sessions.

The record

CVE
CVE-2026-44329
Published
May 27, 2026
Updated
May 27, 2026
Vendor
free5GC
Product
free5GC
Classifications
CWE-862, CWE-306, T1210
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 27, 2026CVE publishedPublication date reported by the CVE source.
  2. May 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 4.2.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

free5GC · free5GCversion=< 4.2.2

Published CVSS scores

10.0GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-862Missing Authorization
CWE-306Missing Authentication for Critical Function
T1210Exploitation of Remote Services

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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