CVE-2026-1683
Free5Gc ≤ 4.1.0
Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XSummary
CVE-2026-1683 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 Exploitation for Privilege Escalation (T1068); ranked at the 47th 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 map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-1683 is a denial-of-service vulnerability affecting Free5GC SMF versions up to 4.1.0. The issue resides in the HandlePfcpSessionReportRequest function within the file internal/pfcp/handler/handler.go of the PFCP component. Manipulation of this function can trigger a denial of service, as classified under CWE-404 (Improper Resource Shutdown or Release). The vulnerability carries 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 impact on availability but no effects on confidentiality or integrity.
Any remote attacker can exploit this vulnerability without authentication or user interaction, given its network accessibility and low complexity. Successful exploitation leads to a denial of service on the affected SMF instance, potentially disrupting PFCP session reporting and related 5G core network functions.
Advisories recommend deploying a patch to mitigate the issue, with a fix available via GitHub pull request #188 in the free5gc/smf repository. Details and discussion are documented in free5gc/free5gc GitHub issue #804, including exploit disclosure to the public.
The exploit has been publicly disclosed, increasing the risk of active exploitation against unpatched Free5GC SMF deployments.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-5031
Vulnerability Data
A vulnerability has been found in Free5GC SMF up to 4.1.0. Affected by this vulnerability is the function HandlePfcpSessionReportRequest of the file internal/pfcp/handler/handler.go of the component PFCP. The manipulation leads to denial of service. Remote exploitation of the attack is…
more
possible. The exploit has been disclosed to the public and may be used. To fix this issue, it is recommended to deploy a patch.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation can discover missing or incorrect resource releases after code is written.
Engineering principles can require explicit resource acquisition/release patterns that stop improper shutdown from being introduced.
Priority-based resource allocation limits the blast radius when released resources are not returned to the pool.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly include coding standards for correct resource allocation and release.
Runtime monitoring can detect resource exhaustion caused by improper shutdown or release.
Lifecycle management of assets can encompass proper resource release at end-of-life or shutdown.
Capacity management helps surface leaks from unreleased resources but does not prevent the coding flaw.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Including restart, recovery and media-handling instructions reduces the likelihood that resources or sensitive data will be left in an exposed or improperly released state after a failure.