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PatchSiren cyber security CVE debrief

CVE-2026-44317 free5gc CVE debrief

A nil pointer dereference vulnerability in free5GC's Policy Control Function (PCF) allows authenticated attackers to trigger a denial of service via a crafted API request. The flaw exists in the POST /npcf-policyauthorization/v1/app-sessions handler prior to version 4.2.2. When processing application session creation requests with the traffic-routing feature enabled (suppFeat ==

Vendor
free5gc
Product
Unknown
CVSS
MEDIUM 6.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-27
Original CVE updated
2026-05-28
Advisory published
2026-05-27
Advisory updated
2026-05-28

Who should care

Telecommunications operators deploying free5GC-based 5G core networks, network security teams managing 5G infrastructure, and organizations using free5GC for private 5G deployments should prioritize patching.

Technical summary

The vulnerability resides in free5GC's PCF component within the application session authorization handler. When an authenticated request enables traffic-routing feature negotiation (suppFeat ==

Defensive priority

medium

Recommended defensive actions

  • Upgrade free5GC to version 4.2.2 or later
  • Apply commit 508d70b8527a6c8c923179dad450ea01e16b6aeb if patching from source
  • Monitor PCF logs for HTTP 500 errors indicating potential exploitation attempts
  • Validate application session requests contain complete AfRoutReq structures when traffic-routing features are negotiated

Evidence notes

The vulnerability was disclosed through GitHub Security Advisory GHSA-wwqh-7jm5-gj7w and NVD. The fix commit 508d70b8527a6c8c923179dad450ea01e16b6aeb addresses the nil pointer dereference by adding proper validation before dereferencing routeReq fields.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-44317 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-44317

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-44317 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-44317

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental 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.