Unauthenticated subscription disclosure via missing handler return
Published Apr 16, 2026 · Updated Apr 16, 2026
Information disclosure in free5GC UDR 4.2.1 and earlier allows remote attackers to read Traffic Influence Subscriptions over the SBI. The GET handler sends a 404 for an invalid influenceId but does not return, so it retrieves the requested subscription and appends it to the response. Exploitation requires SBI reachability and a known or guessed subscriptionId; exposed objects can include SUPIs, DNNs, S-NSSAIs, and callback URIs.
Summary
What happened
Information disclosure in free5GC UDR 4.2.1 and earlier allows remote attackers to read Traffic Influence Subscriptions over the SBI. The GET handler sends a 404 for an invalid influenceId but does not return, so it retrieves the requested subscription and appends it to the response. Exploitation requires SBI reachability and a known or guessed subscriptionId; exposed objects can include SUPIs, DNNs, S-NSSAIs, and callback URIs.
The record
- CVE
- CVE-2026-40247
- Published
- Apr 16, 2026
- Updated
- Apr 16, 2026
- Vendor
- free5GC
- Product
- free5GC
- Classifications
- CWE-636, CWE-285, T1213
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 16, 2026CVE publishedPublication date reported by the CVE source.
- Apr 16, 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?
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- Affected versionversion=<= 1.4.2
What conditions does exploitation require?
What is affected?
Published CVSS scores
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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
- GHSA-x5r2-r74c-3w28 curl proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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