CVE-2026-42082Public exploit

Handover disruption via missing concurrent-procedure checks

Published May 27, 2026 · Updated May 27, 2026

Improper security validation in free5GC before 4.2.2 allows remote authenticated users to disrupt handovers through concurrent NAS and N2 procedures. SecurityMode() sends a NAS Security Mode Command without checking for an ongoing N2 handover, while handleHandoverRequiredMain() starts a handover without checking for an active command. Exploitation requires adjacent 5G network access, low privileges, and precise procedure timing; mismatched KAMF-derived keys can cause handover or security-verification failures.

CVSS severity3.7
Low
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper security validation in free5GC before 4.2.2 allows remote authenticated users to disrupt handovers through concurrent NAS and N2 procedures. SecurityMode() sends a NAS Security Mode Command without checking for an ongoing N2 handover, while handleHandoverRequiredMain() starts a handover without checking for an active command. Exploitation requires adjacent 5G network access, low privileges, and precise procedure timing; mismatched KAMF-derived keys can cause handover or security-verification failures.

The record

CVE
CVE-2026-42082
Published
May 27, 2026
Updated
May 27, 2026
Vendor
free5GC
Product
free5GC
Classifications
CWE-358, T1498
Attack vector
adjacent
Privileges
authenticated

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 vectoradjacent
Required privilegesauthenticated

What is affected?

free5GC · free5GCversion=< 4.2.2

Published CVSS scores

3.7GitHubCVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:L

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.

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No observations available

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

Weakness, pattern, technique

CWE-358Improperly Implemented Security Check for Standard
T1498Network Denial of Service

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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