# CVE-2026-46386: Deserialization in openproject

> Attackers can achieve remote code execution in OpenProject Docker deployments due to hardcoded default secrets and unsafe cookie deserialization.

- **Severity:** Critical 9.9 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`)
- **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:** 26 Jun 2026
- **Updated:** 29 Jun 2026
- **Also known as:** GHSA-r85r-gjq2-f83r

## What is CVE-2026-46386?

CVE-2026-46386 is a critical unsafe deserialization vulnerability in opf openproject, published on 26 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

OpenProject is open-source, web-based project management software. Prior to , the official openproject/openproject Docker image ships ENV SECRET_KEY_BASE=OVERWRITE_ME as the default Rails master key. Combined with cookies_serializer = :marshal, this gives any logged-in user a deterministic Marshal-deserialization path reachable via the /my/two_factor_devices cookie reader This vulnerability is fixed in .

Weakness: CWE-798 (Use of Hard-coded Credentials), CWE-502 (Deserialization of Untrusted Data), CWE-1392 (Use of Default Credentials), CWE-1188 (Initialization of a Resource with an Insecure Default)

## Which versions are affected by CVE-2026-46386?


## How do I fix CVE-2026-46386?

No fix has been published for CVE-2026-46386 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-46386 being exploited?

There is no known exploitation of CVE-2026-46386 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-46386 and fix it if it is affected.

What it is: CVE-2026-46386 is a critical unsafe deserialization vulnerability in opf openproject, published on 26 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-46386 in the wild and no public exploit code.

Affected product: opf openproject. 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-2026-46386/ (Markdown: https://insights.sbomify.com/CVE-2026-46386/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-46386
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-46386
- OSV: https://osv.dev/vulnerability/CVE-2026-46386

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-46386/
Summaries are generated and may contain mistakes; the official description above is the record.