# CVE-2026-40246: free5gc UDR improper path validation allows unauthenticated deletion of Traffic Influence Subscriptions

> Unauthenticated attackers can delete arbitrary Traffic Influence Subscriptions in free5GC UDR due to improper path validation logic.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 16 Apr 2026
- **Updated:** 18 Apr 2026
- **Also known as:** GHSA-g9cw-qwhf-24jp, GO-2026-5396

## What is CVE-2026-40246?

CVE-2026-40246 is a high-severity missing authorization vulnerability in free5gc, published on 16 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

free5GC is an open-source implementation of the 5G core network. In versions 1.4.2 and below of the UDR service, the handler for deleting Traffic Influence Subscriptions checks whether the influenceId path segment equals subs-to-notify, but does not return after sending the HTTP 404 response when validation fails. Execution continues and the subscription is deleted regardless. An unauthenticated attacker with access to the 5G Service Based Interface can delete arbitrary Traffic Influence Subscriptions by supplying any value for the influenceId path segment, while the API misleadingly returns a 404 Not Found response. A patched version was not available at the time of publication.

Weakness: CWE-285 (Improper Authorization)

## Which versions are affected by CVE-2026-40246?

3 open source packages ship an affected version, including github.com/free5gc/udr. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/free5gc/udr` | Go | All versions | None |
| `github.com/free5gc/udr` | Go | All versions to 1.4.2 | None |
| `github.com/free5gc/udr` | Go | All versions to 1.4.2 | None |

Products: Free5gc Webconsole.

## How do I fix CVE-2026-40246?

No fix published yet.

## Is CVE-2026-40246 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-40246 exists.

## Other vulnerabilities in free5gc

- [CVE-2023-4659](https://insights.sbomify.com/CVE-2023-4659/): Cross-Site Request Forgery in Free5Gc (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-40246 and fix it if it is affected.

What it is: CVE-2026-40246 is a high-severity missing authorization vulnerability in free5gc, published on 16 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-40246 exists.

Affected packages and fixed versions:
- github.com/free5gc/udr (Go): affected all versions; no fix listed
- github.com/free5gc/udr (Go): affected all versions up to 1.4.2; no fix listed
- github.com/free5gc/udr (Go): affected all versions up to 1.4.2; no fix listed

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-40246/ (Markdown: https://insights.sbomify.com/CVE-2026-40246/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-40246
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-40246
- OSV: https://osv.dev/vulnerability/CVE-2026-40246

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-40246/
Summaries are generated and may contain mistakes; the official description above is the record.