How severe is CVE-2026-44327?

CVE-2026-44327 has a CVSS 3.x base score of 10.0, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity high, and availability high.

Is CVE-2026-44327 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-44327?

CVE-2026-44327 affects Free5gc. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-44327?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2026-44327 have an EU (EUVD) identifier?

Yes. CVE-2026-44327 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-32571.

When was CVE-2026-44327 published?

CVE-2026-44327 was published on 2026-05-27 and last updated on 2026-06-17.

CVE-2026-44327

CVE-2026-44327 is a critical-severity vulnerability in Free5gc with a CVSS 3.x base score of 10.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-306.

Key facts

Severity: Critical (CVSS 3.x base score 10.0)
EPSS exploit prediction: 0% (24th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-32571
Weakness: CWE-306
Affected product: Free5gc
Published: 2026-05-27
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2026-44327?: 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.
How severe is CVE-2026-44327?: CVE-2026-44327 has a CVSS 3.x base score of 10.0, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity high, and availability high.
Is CVE-2026-44327 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-44327?: CVE-2026-44327 affects Free5gc. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-44327?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-44327 have an EU (EUVD) identifier?: Yes. CVE-2026-44327 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-32571.
When was CVE-2026-44327 published?: CVE-2026-44327 was published on 2026-05-27 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:free5gc:free5gc:*:*:*:*:*:*:*:*

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