Authenticated service crash via unsynchronized subscription writes
Published May 27, 2026 · Updated May 27, 2026
Race condition in free5GC before 4.2.2 allows remote authenticated users to crash the BSF service with concurrent subscription PUTs. ReplaceIndividualSubcription reads the global Subscriptions map under RLock but writes a missing entry directly without acquiring its mutex. A valid nbsf-management token and concurrent requests for fresh subscription IDs trigger a fatal Go map error, terminating the BSF process until restart.
Summary
What happened
Race condition in free5GC before 4.2.2 allows remote authenticated users to crash the BSF service with concurrent subscription PUTs. ReplaceIndividualSubcription reads the global Subscriptions map under RLock but writes a missing entry directly without acquiring its mutex. A valid nbsf-management token and concurrent requests for fresh subscription IDs trigger a fatal Go map error, terminating the BSF process until restart.
The record
- CVE
- CVE-2026-44318
- Published
- May 27, 2026
- Updated
- May 27, 2026
- Vendor
- free5GC
- Product
- free5GC
- Classifications
- CWE-362, CWE-820, 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?
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
- Concurrent subscription PUT proof of conceptfunctional · validated
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Technologies
Your stack
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Your stack
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