Authenticated service degradation via nil interface assertion
Published May 27, 2026 · Updated May 27, 2026
Denial of service in free5GC before 4.2.2 allows remote authenticated users to degrade UDR through a crafted DELETE request. The amf-subscriptions removal processor sets USER_NOT_FOUND when UESubsCollection lacks the supplied UE identifier but continues into a Go type assertion on the nil interface, causing a panic. A valid nudr-dr OAuth2 token is required; Gin recovers each panic, so repeated requests increase CPU and log activity without stopping the UDR process.
Summary
What happened
Denial of service in free5GC before 4.2.2 allows remote authenticated users to degrade UDR through a crafted DELETE request. The amf-subscriptions removal processor sets USER_NOT_FOUND when UESubsCollection lacks the supplied UE identifier but continues into a Go type assertion on the nil interface, causing a panic. A valid nudr-dr OAuth2 token is required; Gin recovers each panic, so repeated requests increase CPU and log activity without stopping the UDR process.
The record
- CVE
- CVE-2026-44324
- Published
- May 27, 2026
- Updated
- May 27, 2026
- Vendor
- free5GC
- Product
- free5GC
- Classifications
- CWE-754, CWE-704, T1499.004
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- May 27, 2026CVE publishedPublication date reported by the CVE source.
- 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.
- Affected versionversion=< 4.2.2
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
Public exploit references
- Authenticated UDR DELETE proof of conceptproof of concept · demonstrated
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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