Cyber Resilience

CVE-2026-41136

Free5Gc Amf ≤ 1.4.3

Public PoC
Published
22 April 2026
Modified
23 April 2026
Patch / advisory
CVSS Score v4 5.5
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/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:X
EPSS Score 0.0028 21th percentile
Risk Priority 38 floored blend · peak EPSS

Summary

CVE-2026-41136 is a medium-severity Expected Behavior Violation (CWE-440) vulnerability in Free5Gc Amf. Its CVSS base score is 5.5 (Medium).

Operationally, ranked at the 21th 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 SI-6 (Security and Privacy Function Verification) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

free5GC AMF provides Access & Mobility Management Function (AMF) for free5GC, an an open-source project for 5th generation (5G) mobile core networks. Prior to version 1.4.3, the `HTTPUEContextTransfer` handler in `internal/sbi/api_communication.go` does not include a `default` case in the `Content-Type`…

more

switch statement. When a request arrives with an unsupported `Content-Type`, the deserialization step is silently skipped, `err` remains `nil`, and the processor is invoked with a completely uninitialized `UeContextTransferRequest` object. Version 1.4.3 contains a fix.

CWE(s)

Related Threats

CVEs Like This One

CVE-2026-1975Same product: Free5Gc Free5Gc
CVE-2026-40247Same product: Free5Gc Free5Gc
CVE-2026-1974Same product: Free5Gc Free5Gc
CVE-2025-65562Same product: Free5Gc Free5Gc
CVE-2023-47347Same product: Free5Gc Free5Gc
CVE-2026-44325Same product: Free5Gc Free5Gc
CVE-2026-30653Same product: Free5Gc Free5Gc
CVE-2025-70123Same product: Free5Gc Free5Gc
CVE-2025-70121Same product: Free5Gc Free5Gc
CVE-2026-44329Same product: Free5Gc Free5Gc

Affected Assets

free5gc
amf
≤ 1.4.3
free5gc
free5gc
≤ 4.2.1

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation directly checks whether implemented functions match their specifications.

Security function verification confirms that functions operate according to their defined expected behavior.

Requiring a documented security architecture and design reduces the chance that implementation deviates from intended behavior.

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.

PR.PS-06 full match
prevents

Secure SDLC practices directly enforce specification compliance and catch expected-behavior violations during development.

ID.IM-02 partial match
prevents

Security testing and exercises help discover behavior deviations before deployment.

ID.RA-01 partial match
prevents

Vulnerability identification can surface spec-violating flaws, while eliminating the weakness reduces some vulnerability backlog.

PR.PS-02 partial match
prevents

Routine software maintenance and patching can remediate discovered specification violations.

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.

finds

Security testing in development and acceptance validates that functions behave as specified.

prevents

Secure development life cycle mandates verification against specifications, directly reducing expected-behavior violations.

prevents

Application security requirements explicitly define expected behavior that must be met.

prevents

Secure coding practices enforce adherence to functional specifications during implementation.

finds

Change management can catch specification deviations introduced by modifications.

none

Documented operating procedures reduce the chance that functions deviate from intended behavior.

References