How severe is GHSA-cmpj-2x3g-m7g3?

GHSA-cmpj-2x3g-m7g3 has a CVSS score of 10/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by GHSA-cmpj-2x3g-m7g3?

GHSA-cmpj-2x3g-m7g3 affects the following packages: github.com/free5gc/nef (Go). Ecosystems affected: Go.

How do I fix GHSA-cmpj-2x3g-m7g3?

No patched version of github.com/free5gc/nef has shipped for GHSA-cmpj-2x3g-m7g3 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.

How do I detect GHSA-cmpj-2x3g-m7g3 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/free5gc/nef. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-cmpj-2x3g-m7g3 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-cmpj-2x3g-m7g3?

O3 pinpoints whether GHSA-cmpj-2x3g-m7g3 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-cmpj-2x3g-m7g3 actively exploited in the wild?

No public exploit code has been indexed for GHSA-cmpj-2x3g-m7g3 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was GHSA-cmpj-2x3g-m7g3 published, and has it been updated?

GHSA-cmpj-2x3g-m7g3 was published on May 8, 2026 and was last updated on July 21, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹

🐹 Go

Not in CISA KEV

CRITICAL severity

GHSA-cmpj-2x3g-m7g3

CRITICALFix: free5gc/nef#23

GHSA-cmpj-2x3g-m7g3 is a critical-severity (CVSS 10) vulnerability in github.com/free5gc/nef. O3 Security confirms whether GHSA-cmpj-2x3g-m7g3 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

free5GC's NEF nnef-oam route group is unauthenticated; no-token requests reach the OAM handler

Also known asCVE-2026-44327GO-2026-5326

Published

May 8, 2026

Updated

Jul 21, 2026

Affected

1 pkg

Patched

None yet

Exploits

None indexed

Exploitation data as of Jul 21, 2026 · OSV.dev, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected

🐹github.com/free5gc/nef

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

Summary

free5GC's NEF mounts the nnef-oam route group without inbound OAuth2/bearer-token authorization. A network attacker who can reach NEF on the SBI can hit the OAM route with no Authorization header at all and the handler returns 200 OK. The current OAM handler is a stub that returns null, but the structural defect is route-group-scoped: the entire OAM route group has no inbound auth middleware, so every future OAM operation added to this group inherits the missing auth boundary by default. Same root cause as the NEF traffic-influence and PFD-management findings.

Details

Validated against the NEF container in the official Docker compose lab.

Source repo tag: v4.2.1
Running Docker image: free5gc/nef:v4.2.0
Runtime NEF commit: 5ce35eab
Docker validation date: 2026-03-11

NEF advertises OAuth2 setting receive from NRF: true, yet the OAM route group is mounted without any inbound auth middleware and answers unauthenticated GETs with 200 OK.

Code evidence (paths in free5gc/nef):

OAM route group mounted without auth middleware: NFs/nef/internal/sbi/server.go:60
OAM route exposed at /: NFs/nef/internal/sbi/api_oam.go:9
OAM processor returns 200 OK directly: NFs/nef/internal/sbi/processor/oam.go:9
NEF context only exposes outbound token acquisition (GetTokenCtx); there is no inbound authorization path: NFs/nef/internal/context/nef_context.go:153

PoC

Reproduced against the running NEF at http://10.100.200.19:8000 with no Authorization header:

curl -i http://10.100.200.19:8000/nnef-oam/v1/

Observed output:

HTTP/1.1 200 OK
null

NEF container logs (docker logs nef) show the request being served while OAuth is enabled:

[INFO][NEF][GIN] | 200 | GET | /nnef-oam/v1/

Impact

Missing inbound authentication (CWE-306) and authorization (CWE-862) on the NEF OAM SBI route group. Severity is scored against the OAM route group's intended capability surface (Operations / Administration / Maintenance), NOT against the current stub handler. The current handler is a stub that returns null, but the defect is route-group-scoped: there is no auth middleware on the group at all, so every future OAM operation added behind this group inherits the missing inbound auth boundary by default.

Any party that can reach NEF on the SBI can:

Probe and enumerate the OAM route surface anonymously today.
Hit any future OAM-group endpoint (read, modify, restart-style operations) anonymously, because the auth boundary does not exist for this group.

Operators who assume OAuth2 setting receive from NRF: true enforces inbound auth on NEF are wrong for this route group.

Affected: free5gc v4.2.1.

Upstream issue: https://github.com/free5gc/free5gc/issues/861 Upstream fix: https://github.com/free5gc/nef/pull/23

Affected Packages

1 total

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/free5gc/nef`	all versions	No fix

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/free5gc/nef. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of github.com/free5gc/nef has shipped for GHSA-cmpj-2x3g-m7g3 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-cmpj-2x3g-m7g3 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-cmpj-2x3g-m7g3. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Summary free5GC's NEF mounts the `nnef-oam` route group without inbound OAuth2/bearer-token authorization. A network attacker who can reach NEF on the SBI can hit the OAM route with no `Authorization` header at all and the handler returns `200 OK`. The current OAM handler is a stub that returns `null`, but the structural defect is route-group-scoped: the entire OAM route group has no inbound auth middleware, so every future OAM operation added to this group inherits the missing auth boundary by default. Same root cause as the NEF traffic-influence and PFD-management findings. ### Details

O3 Security · Impact-Aware SCA

Is GHSA-cmpj-2x3g-m7g3 in your dependencies?

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