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TI-2026-29763 Aliases CVE-2026-41135GHSA-98cp-84m9-q3qp

free5GC PCF: Memory Leak via CORS Middleware Registration in HTTP Handler Leads to Denial of Service

Priority HIGH 72CWE-400Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-400.

Summary

free5GC UDR is the Policy Control Function (PCF) for free5GC, an an open-source project for 5th generation (5G) mobile core networks. A memory leak vulnerability in versions prior to 1.4.3 allows any unauthenticated attacker with network access to the PCF SBI interface to cause uncontrolled memory growth by sending repeated HTTP requests to the OAM endpoint. The root cause is a `router.Use()` call inside an HTTP handler that registers a new CORS middleware on every incoming request, permanently growing the Gin router's handler chain. This leads to progressive memory exhaustion and eventual Denial of Service of the PCF, preventing all UEs from obtaining AM and SM policies and blocking 5G session establishment. Version 1.4.3 contains a patch.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00515 44th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed pcf (free5gc): 1.4.3github.com/free5gc/pcf (Go): 1.4.3

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
free5gcpcfbefore 1.4.31.4.3Patch availableCNA
—github.com/free5gc/pcf (Go)before 1.4.31.4.3Patch availableGHSA-98cp-84m9-q3qp
  • pcf Vendorfree5gc Affected before 1.4.3 Fixed in 1.4.3 Patch available CNA
  • github.com/free5gc/pcf (Go) Vendor— Affected before 1.4.3 Fixed in 1.4.3 Patch available GHSA-98cp-84m9-q3qp

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:free5gc:free5gc:*:*:*:*:*:*:*:*up to 4.2.1Vulnerablefree5gc
cpe:2.3:a:free5gc:pcf:*:*:*:*:*:*:*:*before 1.4.3Vulnerablefree5gc
  • cpe:2.3:a:free5gc:free5gc:*:*:*:*:*:*:*:* Versions up to 4.2.1 Vulnerable ·free5gc
  • cpe:2.3:a:free5gc:pcf:*:*:*:*:*:*:*:* Versions before 1.4.3 Vulnerable ·free5gc

Remediation

  • Fix · CNA pcf (free5gc) Fixed in 1.4.3
  • Fix · GHSA-98cp-84m9-q3qp github.com/free5gc/pcf (Go) Fixed in 1.4.3 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-41135
  2. 2026-10-03 Alias added: GHSA-98cp-84m9-q3qp

References

Exploit 1

Patch 1

Advisory 1

Other 1

  • TI-2026-32298 Incorrect authorization in free5gc CVSS 3.1CRITICAL 10.0
  • TI-2026-32297 free5GC: SMF UPI management interface lacks auth middleware; unauthenticated topology read/write requests reach handlers CVSS 3.1CRITICAL 10.0
  • TI-2026-32295 free5GC: NEF nnef-oam route group is unauthenticated; no-token requests reach the OAM handler CVSS 3.1CRITICAL 10.0
  • TI-2025-39412 free5gc v4.1.0 and before is vulnerable to Buffer Overflow. CVSS 3.1CRITICAL 9.8
  • TI-2026-32294 Missing authorization in free5gc CVSS 3.1CRITICAL 9.4
  • TI-2026-32283 Missing authorization in free5gc CVSS 3.1CRITICAL 9.4
See all 58 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences