# CVE-2026-40245: Free5GC: UDR nudr-dr influenceData/subs-to-notify leaks SUPI in error response body without authentication

> Unauthenticated attackers can retrieve sensitive subscriber identifiers (SUPI/IMSI) from Free5GC UDR service via a parameterless HTTP GET request due to missing error handling.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Apr 2026
- **Updated:** 16 Apr 2026
- **Also known as:** GHSA-wrwh-rpq4-87hf, GO-2026-5722

## What is CVE-2026-40245?

CVE-2026-40245 is a high-severity vulnerability in Free5gc Free5gc, published on 15 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 Linux Foundation project for 5th generation (5G) mobile core networks. Versions 4.2.1 and below contain an information disclosure vulnerability in the UDR (Unified Data Repository) service. The handler for GET /nudr-dr/v2/application-data/influenceData/subs-to-notify sends an HTTP 400 error response when required query parameters are missing but does not return afterward. Execution continues into the processor function, which queries the data repository and appends the full list of Traffic Influence Subscriptions, including SUPI/IMSI values, to the response body. An unauthenticated attacker with network access to the 5G Service Based Interface can retrieve stored subscriber identifiers with a single parameterless HTTP GET request. The SUPI is the most sensitive subscriber identifier in 5G networks, and its exposure undermines the privacy guarantees of the 3GPP SUCI concealment mechanism at the core network level. A similar bypass exists when sending a malformed snssai parameter due to the same missing return pattern.

Weakness: CWE-209 (Generation of Error Message Containing Sensitive Information), CWE-202 (Exposure of Sensitive Information Through Data Queries), CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2026-40245?

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 Free5gc.

## How do I fix CVE-2026-40245?

Upgrade to a fixed version.

## Is CVE-2026-40245 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-40245 exists.

## Other vulnerabilities in Free5gc Free5gc

- [CVE-2026-44327](https://insights.sbomify.com/CVE-2026-44327/): free5GC: NEF nnef-oam route group is unauthenticated; no-token requests reach the OAM handler (critical 10.0)
- [CVE-2026-44329](https://insights.sbomify.com/CVE-2026-44329/): free5GC's SMF UPI management interface lacks auth middleware; unauthenticated topology read/write requests reach handlers (critical 10.0)
- [CVE-2026-44330](https://insights.sbomify.com/CVE-2026-44330/): free5GC's NEF nnef-pfdmanagement API is unauthenticated; forged bearer tokens can read PFD data and create/delete PFD subscriptions (critical 10.0)
- [CVE-2025-63679](https://insights.sbomify.com/CVE-2025-63679/): Memory corruption in n/a (critical 9.8)
- [CVE-2026-44315](https://insights.sbomify.com/CVE-2026-44315/): free5GC's NEF 3gpp-pfd-management API is unauthenticated; forged bearer tokens can create, read, and delete PFD transactions (critical 9.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-40245 and fix it if it is affected.

What it is: CVE-2026-40245 is a high-severity vulnerability in Free5gc Free5gc, published on 15 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-2026-40245 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-2026-40245/ (Markdown: https://insights.sbomify.com/CVE-2026-40245/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-40245
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-40245
- OSV: https://osv.dev/vulnerability/CVE-2026-40245

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-40245/
Summaries are generated and may contain mistakes; the official description above is the record.