CVE-2026-44321: free5GC is an open-source implementation of the 5G core network

Q: How do I fix CVE-2026-44321?

free5gc: upgrade to 4.2.2. Exact commands for each OS are on this page.

Q: Is CVE-2026-44321 being exploited?

CVE-2026-44321 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-44321 affect?

CVE-2026-44321 affects free5gc. Severity is high (CVSS 7.5). free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's SMF mounts the UPI management route group without inbound OAuth2 middleware. The POST /upi/v1/upNodesLinks create-or-update handler accepts attacker-

Q: How urgent is CVE-2026-44321?

Priority 44/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

This week

HIGH 7.5REMOTEUPGRADE

CVE-2026-44321 is a high-severity flaw (CVSS 7.5) affecting free5gc. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's SMF mounts the UPI management route group without inbound OAuth2 middleware. The POST /upi/v1/upNodesLinks create-or-update handler accepts attacker-controlled JSON and passes it directly into UpNodesFromConfiguration(), which calls logger.InitLog.Fatalf(...) on several validation failures. One confirmed path is the UE-IP-pool overlap check: a single unauth

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 70%)
CISA exploited list	No
Weakness	CWE-306, CWE-617, CWE-862
Published	2026-05-27
Last modified	2026-10-14

Publisher (CNA): GitHub, Inc. · Vendor: free5gc

Last updated 2026-10-14 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-27 17:16 UTCPublished CVE record published
2026-10-14 20:10 UTCUpdated Record last modified

free5gc free5gc UPGRADE

Affected: < 4.2.2

Fixed in: 4.2.2

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy free5gc || rpm -q free5gc || free5gc --version

2. UPGRADE to 4.2.2 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade free5gc

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade free5gc

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-44321?

free5gc: upgrade to 4.2.2. Exact commands for each OS are on this page.

Is CVE-2026-44321 being exploited?

CVE-2026-44321 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-44321 affect?

CVE-2026-44321 affects free5gc. Severity is high (CVSS 7.5). free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's SMF mounts the UPI management route group without inbound OAuth2 middleware. The POST /upi/v1/upNodesLinks create-or-update handler accepts attacker-

How urgent is CVE-2026-44321?

Priority 44/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

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CVE-2026-44329 CRITICAL 10.0 UPGRADE free5GC is an open-source implementation of the 5G core network
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References

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