CVE-2026-1974
Published: 06 February 2026
Summary
CVE-2026-1974 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 48.1th 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 SC-5 (Denial-of-service Protection) and SI-2 (Flaw Remediation).
Deeper analysis
CVE-2026-1974 is a denial-of-service vulnerability affecting Free5GC versions up to 4.1.0, an open-source implementation of a 5G core network. The issue resides in the ResolveNodeIdToIp function within the file internal/sbi/processor/datapath.go of the SMF (Session Management Function) component. It is classified under CWE-404 (Improper Resource Shutdown or Release) with 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 due to its network-accessible nature and low impact on availability.
The vulnerability enables remote attackers with no authentication or privileges to exploit it over the network with low complexity. By manipulating the affected function, attackers can trigger a denial of service, disrupting the SMF's availability without impacting confidentiality or integrity. A public exploit is available, increasing the risk of active exploitation.
Advisories and references, including GitHub issues #816 and the related pull request #189 in the free5gc/smf repository, confirm a patch is available to address the issue. Security practitioners should update to a patched version of Free5GC beyond 4.1.0 and monitor the project's repository for further guidance. The VulDB entry (ctiid.344496) provides additional details on the vulnerability.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-5604
Vulnerability details
A vulnerability was identified in Free5GC up to 4.1.0. This affects the function ResolveNodeIdToIp of the file internal/sbi/processor/datapath.go of the component SMF. The manipulation leads to denial of service. Remote exploitation of the attack is possible. The exploit is publicly…
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available and might be used. It is recommended to apply a patch to fix this issue.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Remote unauthenticated exploitation of public-facing SMF service (T1190) to trigger application DoS via resource handling flaw (T1499.004).
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly requires timely remediation of the publicly disclosed flaw in Free5GC SMF ResolveNodeIdToIp by applying the available patch beyond version 4.1.0.
Explicitly mandates protection mechanisms against network-based denial-of-service attacks targeting the SMF component's availability.
Requires validation of inputs to ResolveNodeIdToIp, which would block the manipulation that triggers improper resource release and DoS.