free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, 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. This vulnerability is fixed in 4.2.2.
CVE-2026-44327
Score 10.0 from GitHub Security Advisory (severity: CRITICAL) published 2026-05-08. NVD baseline CVSS 10.0; sources differ by 0.0.
- High severity, but no confirmed exploitation yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 10.0
- EG Score
- 10.0(medium)
- EPSS
- 23.4%
- KEV
- Not listed
Published
May 27, 2026
Last Modified
May 28, 2026
Advisory Details (3)
Auto-updated Jul 22, 2026NEF nnef-oam route group is unauthenticated; no-token requests reach the OAM handler · Advisory · free5gc/free5gc · GitHub
https://github.com/free5gc/free5gc/security/advisories/GHSA-cmpj-2x3g-m7g3fix(sbi): enforce inbound OAuth2 on NEF service routes
Upstream fix in progress (PR #23 · free5gc/nef, state=closed)
https://github.com/free5gc/nef/pull/23[Bugs] NEF `nnef-oam` is unauthenticated: no-token requests can access the OAM route · Issue #861 · free5gc/free5gc · GitHub
https://github.com/free5gc/free5gc/issues/861Vendor Advisories for CVE-2026-44327(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Patch Availability(1)
| Vendor / Ecosystem | Fixed in / Patch | Released | Source |
|---|---|---|---|
| go | github.com/free5gc/nef | — | ghsa |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Affected Packages
(1 across 1 ecosystem)
Go(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| github.com/free5gc/nef | — | — | — |
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 7× in last 7d / 58× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
Showing the most recent 100 of 194 total refreshes for this CVE.
- 2026-07-22 14:08 UTCEPSS rescore
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- 2026-07-11 23:17 UTCGHSA enrichment
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- 2026-07-01 09:30 UTCGHSA enrichment
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- 2026-06-18 03:38 UTCGHSA enrichment
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- 2026-06-17 17:53 UTCEPSS rescore
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- 2026-06-15 17:49 UTCEPSS rescore
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- 2026-06-13 03:07 UTCGHSA enrichment
- 2026-06-12 23:12 UTCEPSS rescore
- 2026-06-12 23:12 UTCEPSS rescore
- 2026-06-12 22:46 UTCGHSA enrichment
- 2026-06-12 18:27 UTCGHSA enrichment
Related CVEs(same product + same CWE)
Same product
4 showngo:github.com/free5gc/nef
Same CWE
10 shownCWE-306 · CWE-862
- CVE-2011-10013EG 10.0CRITICAL
- CVE-2014-125124EG 10.0CRITICAL
- CVE-2017-2637EG 10.0EPSS 91%CRITICAL
- CVE-2010-5326EG 10.0 KEVEPSS 97%CRITICAL
- CVE-2013-3960EG 9.9CRITICAL
- CVE-2012-10030EG 9.8CRITICAL
- CVE-2015-10143EG 9.8CRITICAL
- CVE-2016-11036EG 9.8CRITICAL
- CVE-2014-3449EG 9.8CRITICAL
- CVE-2006-0062EG 9.8CRITICAL
Frequently asked(5)
What is CVE-2026-44327?
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