Read the docs
TI-2026-29042 Aliases CVE-2026-40248GHSA-jgq2-qv8v-5cmj

free5gc UDR improper path validation allows unauthenticated creation and modification of Traffic Influence Subscriptions

Priority HIGH 77CWE-285Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Security bypass
Confidentiality · integrity · availability
None · High · None
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-285.

Summary

free5GC is an open-source implementation of the 5G core network. In versions 4.2.1 and below of the UDR service, the handler for creating or updating Traffic Influence Subscriptions checks whether the influenceId path segment equals subs-to-notify, but does not return after sending the HTTP 404 response when validation fails. Execution continues and the subscription is created or overwritten regardless. An unauthenticated attacker with access to the 5G Service Based Interface can create or overwrite arbitrary Traffic Influence Subscriptions, including injecting attacker-controlled notificationUri values and arbitrary SUPIs, by supplying any value for the influenceId path segment. A patched version was not available at the time of publication.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00427 37th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix No fix listed No fixed version in the sources yet

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
free5gcfree5gcup to 1.4.2—No fix listedCNA
—github.com/free5gc/udr (Go)up to 1.4.2—No fix listedGHSA-jgq2-qv8v-5cmj
  • free5gc Vendorfree5gc Affected up to 1.4.2 Fixed in — No fix listed CNA
  • github.com/free5gc/udr (Go) Vendor— Affected up to 1.4.2 Fixed in — No fix listed GHSA-jgq2-qv8v-5cmj

CPE configurations NVD · 1

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

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-40248
  2. 2026-10-03 Alias added: GHSA-jgq2-qv8v-5cmj

References

Exploit 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