CVE-2026-75439 Free5GC CVE debrief

Who should care

Defenders responsible for Free5GC deployments, especially those using UPF components, should assess potential exposure and verify configurations to prevent denial-of-service attacks.

Why it matters

CVE-2026-75439 is a denial-of-service vulnerability in Free5GC v.4.2.2, affecting the UPF component. Defenders should verify exposure, review configurations, and monitor systems to prevent and respond to potential attacks.

• Potential denial-of-service attacks against Free5GC deployments
• Verification of UPF component usage and configurations
• Monitoring for unusual activity or outages in Free5GC systems

Technical summary

The CVE record describes a denial-of-service vulnerability in Free5GC v.4.2.2, affecting the UPF component. The CVSS score is 7.5 with a HIGH severity rating. The vulnerability allows a remote attacker to cause a denial of service via the UPF component. The vulnerability has not been modified since its publication on 2026-09-04T21:17:25.583Z. Defenders should prioritize verifying exposure in Free5GC deployments, especially those using UPF components, and assess potential denial-of-service risks. Limited information is available about the vulnerability.

Defensive priority

Defenders should prioritize verifying exposure in Free5GC deployments, especially those using UPF components, and assess potential denial-of-service risks.

Recommended defensive actions

• Verify Free5GC deployments for UPF component usage and assess potential exposure
• Review and update Free5GC configurations to prevent denial-of-service attacks
• Monitor Free5GC systems for unusual activity or outages
• Perform a thorough review of UPF component usage
• Check for any existing mitigations or patches
• Consider implementing compensating controls for exposed systems
• Track exceptions and retest remediated assets

Evidence notes

The CVE record and NVD entry provide limited information about the vulnerability, with a CVSS score of 7.5 and a HIGH severity rating. The vulnerability affects Free5GC v.4.2.2 and allows a remote attacker to cause a denial of service via the UPF component. Evidence is limited to CVE and NVD data. Defenders should verify exposure and review configurations.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.