CVE-2026-42459Public exploitNetwork attack vector

Internal infrastructure disclosure via unvalidated SUPI paths

Published May 27, 2026 · Updated May 27, 2026

Information disclosure in free5GC UDM before 4.2.2 allows remote attackers to expose internal UDR details via crafted SUPI paths. Six nudm-sdm GET handlers omit validator.IsValidSupi(), pass control-character input into an internal UDR URL, and echo the parser error in a 500 response. The request needs network access to the UDM Service Based Interface; disclosure is limited to the UDR host, port, API path, version, and naming details.

CVSS severityUnavailable
Unscored
EPSS probability0.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in free5GC UDM before 4.2.2 allows remote attackers to expose internal UDR details via crafted SUPI paths. Six nudm-sdm GET handlers omit validator.IsValidSupi(), pass control-character input into an internal UDR URL, and echo the parser error in a 500 response. The request needs network access to the UDM Service Based Interface; disclosure is limited to the UDR host, port, API path, version, and naming details.

The record

CVE
CVE-2026-42459
Published
May 27, 2026
Updated
May 27, 2026
Vendor
free5GC
Product
free5GC
Classifications
CWE-209, CWE-20, T1190
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

7.7GitHub Advisory DatabaseCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-209Generation of Error Message Containing Sensitive Information
CWE-20Improper Input Validation
T1190Exploit Public-Facing Application

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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