# CVE-2026-41896: Coolify: Unauthenticated Deployment Trigger via Webhook HMAC Bypass with Null Secret

> Unauthenticated attackers can forge webhook signatures using a null secret to trigger unauthorized deployments in Coolify.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 29 Jun 2026
- **Updated:** 30 Jun 2026
- **Also known as:** GHSA-w8wm-r924-f65v

## What is CVE-2026-41896?

CVE-2026-41896 is a high-severity authentication bypass vulnerability in coollabsio coolify, published on 29 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Coolify is an open-source and self-hostable tool for managing servers, applications, and databases. Prior to 4.0.0-beta.474, the HMAC key is the application's manual_webhook_secret_github field, which is used by Coolify's webhook endpoints to validate incoming requests, is nullable with no default — meaning newly created applications have a null webhook secret. PHP's hash_hmac() function silently coerces a null key to an empty string ''. So when the secret is null, the server computes hash_hmac('sha256', $payload, '') — a deterministic value that any attacker can calculate independently. By sending X-Hub-Signature-256: sha256=<hash_hmac('sha256', payload, '')>, an unauthenticated attacker can forge a valid signature and trigger deployments. This vulnerability is fixed in 4.0.0-beta.474.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2026-41896?


## How do I fix CVE-2026-41896?

No fix has been published for CVE-2026-41896 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-41896 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-41896 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-41896 and fix it if it is affected.

What it is: CVE-2026-41896 is a high-severity authentication bypass vulnerability in coollabsio coolify, published on 29 Jun 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-2026-41896 exists.

Affected product: coollabsio coolify. 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-2026-41896/ (Markdown: https://insights.sbomify.com/CVE-2026-41896/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-41896
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-41896
- OSV: https://osv.dev/vulnerability/CVE-2026-41896

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-41896/
Summaries are generated and may contain mistakes; the official description above is the record.