CVE-2026-1682
Published: 30 January 2026
Summary
CVE-2026-1682 is a medium-severity Improper Resource Shutdown or Release (CWE-404) vulnerability in Free5Gc Free5Gc. Its CVSS base score is 5.5 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 15.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation).
Deeper analysis
CVE-2026-1682 is a null pointer dereference vulnerability (CWE-404, CWE-476) in the Free5GC SMF (Session Management Function) up to version 4.1.0. The flaw affects the HandlePfcpAssociationReleaseRequest function within the PFCP UDP Endpoint component, specifically in the file internal/pfcp/handler/handler.go. It has a CVSS v3.1 base score of 5.3 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L), indicating medium severity with low availability impact but no confidentiality or integrity effects.
The vulnerability can be exploited remotely by unauthenticated attackers over the network with low complexity and no user interaction required. Successful exploitation triggers a null pointer dereference, potentially causing a denial-of-service condition through application crashes or instability in the PFCP UDP Endpoint handling.
GitHub advisories in free5gc/free5gc issue #794 and related comments detail the issue, with a patch available in free5gc/smf pull request #188. Security practitioners should apply this patch to remediate the vulnerability.
An exploit for this issue has been publicly disclosed, increasing the risk of targeted attacks against exposed Free5GC SMF deployments.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-5030
Vulnerability details
A flaw has been found in Free5GC SMF up to 4.1.0. Affected is the function HandlePfcpAssociationReleaseRequest of the file internal/pfcp/handler/handler.go of the component PFCP UDP Endpoint. Executing a manipulation can lead to null pointer dereference. The attack may be launched…
more
remotely. The exploit has been published and may be used. A patch should be applied to remediate this issue.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Null dereference in network-exposed PFCP handler enables remote unauthenticated exploitation of public-facing app (T1190) resulting in application DoS via crafted requests (T1499.004).
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly requires applying the published patch (free5gc/smf#188) that eliminates the null pointer dereference in HandlePfcpAssociationReleaseRequest.
Requires validation of PFCP UDP messages before processing, preventing the malformed Association Release Request from reaching the dereference site.
Ensures the PFCP handler gracefully manages unexpected null conditions instead of crashing the SMF process.