Cyber Resilience

CVE-2025-66720

HighPublic PoC

Published: 23 January 2026

Published
23 January 2026
Modified
11 February 2026
KEV Added
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Patch
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CVSS Score v3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0003 8.1th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-66720 is a high-severity NULL Pointer Dereference (CWE-476) vulnerability in Free5Gc Pcf. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 8.1th 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-11 (Error Handling).

Deeper analysis

CVE-2025-66720, published on 2026-01-23, is a null pointer dereference vulnerability (CWE-476) affecting free5gc pcf version 1.4.0. The flaw resides in the file internal/sbi/processor/ampolicy.go within the function HandleDeletePoliciesPolAssoId. free5gc is an open-source implementation of a 5G core network, and pcf refers to its Policy Control Function component. The vulnerability carries a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H), highlighting its potential for high availability impact.

An attacker can exploit this vulnerability remotely over the network without authentication, privileges, or user interaction, requiring only low attack complexity. Exploitation triggers a null pointer dereference, causing the PCF service to crash and resulting in a denial-of-service condition that disrupts policy control operations in the 5G core network.

The free5gc project documented the issue in GitHub issue #726 (https://github.com/free5gc/free5gc/issues/726) and addressed it with a patch in pull request #57 of the pcf repository (https://github.com/free5gc/pcf/pull/57). Practitioners running free5gc pcf 1.4.0 should apply the patch or upgrade to a fixed version to mitigate the risk.

EU & UK References

Vulnerability details

Null pointer dereference in free5gc pcf 1.4.0 in file internal/sbi/processor/ampolicy.go in function HandleDeletePoliciesPolAssoId.

CWE(s)
CWE-476

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
attack.mitre.org →
Why these techniques?

Null pointer dereference enables remote unauthenticated exploitation to crash the PCF service (Endpoint DoS via application exploitation).

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

CVEs Like This One

CVE-2026-1739Same product: Free5Gc Pcf
CVE-2026-41135Same product: Free5Gc Pcf
CVE-2025-69252Same vendor: Free5Gc
CVE-2026-26025Same vendor: Free5Gc
CVE-2026-26024Same vendor: Free5Gc
CVE-2026-33063Same vendor: Free5Gc
CVE-2026-1973Same vendor: Free5Gc
CVE-2026-1976Same vendor: Free5Gc
CVE-2026-44322Same vendor: Free5Gc
CVE-2026-25501Same vendor: Free5Gc

Affected Assets

free5gc
pcf
1.4.0

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SI-2 Flaw Remediation good match
prevent

Directly mitigates the null pointer dereference by requiring timely application of the vendor patch or upgrade for free5gc pcf 1.4.0.

SC-5 Denial-of-service Protection good match
prevent

Protects the Policy Control Function against remote unauthenticated denial-of-service attacks that trigger the service crash via network traffic restrictions.

SI-11 Error Handling good match
prevent

Ensures robust error handling in the HandleDeletePoliciesPolAssoId function to avoid exploitable crashes from null pointer dereferences.

References