# CVE-2026-33975: twenty-server SSRF protection bypass via IPv4-mapped IPv6 address normalization

> Authenticated attackers can bypass SSRF protections using IPv4-mapped IPv6 addresses to access internal networks and steal cloud credentials.

- **Severity:** High 8.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 5 May 2026
- **Updated:** 6 May 2026
- **Also known as:** GHSA-vrcj-hv2q-c58m

## What is CVE-2026-33975?

CVE-2026-33975 is a high-severity server-side request forgery vulnerability in twentyhq twenty, published on 5 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Twenty is an open source CRM built with NestJS (Node.js). In versions 1.18.0 and earlier, the SSRF protection in twenty-server's SecureHttpClientService can be bypassed using IPv4-mapped IPv6 addresses in URL IP literals. Node.js's URL parser normalizes IPv4-mapped IPv6 addresses to compressed hex form (e.g., ::ffff:169.254.169.254 becomes ::ffff:a9fe:a9fe), but the isPrivateIp utility only recognizes the dotted-decimal notation. As a result, the hex form passes the SSRF check unchecked. Additionally, the socket lookup validation event does not fire for IP literal addresses, bypassing the second validation layer. An authenticated user can reach any internal IP, including cloud metadata endpoints, to exfiltrate credentials such as IAM keys.

Weakness: CWE-918 (Server-Side Request Forgery)

## Which versions are affected by CVE-2026-33975?


## How do I fix CVE-2026-33975?

No fix has been published for CVE-2026-33975 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-33975 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-33975 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-33975 and fix it if it is affected.

What it is: CVE-2026-33975 is a high-severity server-side request forgery vulnerability in twentyhq twenty, published on 5 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-33975 exists.

Affected product: twentyhq twenty. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-33975/ (Markdown: https://insights.sbomify.com/CVE-2026-33975/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33975
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33975
- OSV: https://osv.dev/vulnerability/CVE-2026-33975

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-33975/
Summaries are generated and may contain mistakes; the official description above is the record.