How severe is CVE-2026-33064?

No CVSS score has been assigned to CVE-2026-33064 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-33064?

CVE-2026-33064 affects the following packages: github.com/free5gc/udm (Go). Ecosystems affected: Go.

How do I fix CVE-2026-33064?

Update github.com/free5gc/udm to 1.4.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-33064 is resolved across your whole dependency graph.

How do I detect CVE-2026-33064 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/free5gc/udm, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-33064 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 CVE-2026-33064?

O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-33064 can be triaged on real exposure rather than presence alone.

Is CVE-2026-33064 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-33064 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.

What is the EPSS score for CVE-2026-33064?

CVE-2026-33064 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 41th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-33064?

CVE-2026-33064 is classified as CWE-478 (CWE-478), NULL Pointer Dereference (CWE-476). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-33064 published, and has it been updated?

CVE-2026-33064 was published on March 20, 2026 and was last updated on August 12, 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

CVE-2026-33064 — udm

Fix: free5gc/udm@65d7070

CVE-2026-33064 is a CWE-478 vulnerability in github.com/free5gc/udm. A fix is available for github.com/free5gc/udm — see the affected versions and patch details below.

free5GC UDM DataChangeNotification Procedure Panic Due to Nil Pointer Dereference

Also known asGHSA-7g27-v5wj-jr75GO-2026-4757

Published

Mar 20, 2026

Updated

Aug 12, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

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

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-33064.

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs41th percentile — riskier than 41% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Real-World Exposure

1 pkg affected

🐹github.com/free5gc/udm

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

Impact
This is a NULL Pointer Dereference vulnerability leading to Denial of Service.

Security Impact: A remote attacker can cause the UDM service to panic and crash by sending a crafted POST request to the /sdm-subscriptions endpoint with a malformed URL path containing path traversal sequences (../) and a large JSON payload. The DataChangeNotificationProcedure function in notifier.go attempts to access a nil pointer without proper validation, causing a complete service crash with "runtime error: invalid memory address or nil pointer dereference".
Functional Impact: The service crashes completely, requiring manual restart. All UDM functionality is disrupted until recovery.
Affected Parties: All deployments of free5GC v4.0.1 using the UDM HTTP callback functionality.

Patches
Yes, the issue has been patched.
The fix is implemented in PR free5gc/udm#78.
Users should upgrade to the next release of free5GC that includes this commit.

Workarounds
There is no direct workaround at the application level. The recommendation is to apply the provided patch or implement API gateway-level filtering to block requests containing path traversal sequences.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/free5gc/udm`	all versions	1.4.2`go get github.com/free5gc/udm@v1.4.2`

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/udm, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/free5gc/udm to 1.4.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-33064 is resolved across your whole dependency graph.
Workarounds
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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-33064 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2026-33064. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

**Impact** This is a NULL Pointer Dereference vulnerability leading to Denial of Service. - **Security Impact**: A remote attacker can cause the UDM service to panic and crash by sending a crafted POST request to the `/sdm-subscriptions` endpoint with a malformed URL path containing path traversal sequences (`../`) and a large JSON payload. The `DataChangeNotificationProcedure` function in `notifier.go` attempts to access a nil pointer without proper validation, causing a complete service crash with "runtime error: invalid memory address or nil pointer dereference". - **Functional Impact

O3 Security · Impact-Aware SCA

Is CVE-2026-33064 in your dependencies?

O3 Security finds CVE-2026-33064 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

Scan my dependencies How O3 SCA works