# CVE-2026-1699: Code injection in Eclipse Theia - Website

> Attackers can execute arbitrary code in CI via pull_request_target, exfiltrating secrets and modifying the website or packages.

- **Severity:** Critical 10.0 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 30 Jan 2026
- **Updated:** 2 Feb 2026
- **Also known as:** GHSA-r738-32mw-386p

## What is CVE-2026-1699?

CVE-2026-1699 is a critical code injection vulnerability in Eclipse Theia - Website, published on 30 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the Eclipse Theia Website repository, the GitHub Actions workflow .github/workflows/preview.yml used pull_request_target trigger while checking out and executing untrusted pull request code. This allowed any GitHub user to execute arbitrary code in the repository's CI environment with access to repository secrets and a GITHUB_TOKEN with extensive write permissions (contents:write, packages:write, pages:write, actions:write). An attacker could exfiltrate secrets, publish malicious packages to the eclipse-theia organization, modify the official Theia website, and push malicious code to the repository.

Weakness: CWE-829 (Inclusion of Functionality from Untrusted Control Sphere)

## Which versions are affected by CVE-2026-1699?

It affects 1 product.


Products: Eclipse Theia Website.

## How do I fix CVE-2026-1699?

No fix has been published for CVE-2026-1699 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-1699 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-1699 exists.

Public exploit code:

- Authorized security-research lab reproducing CVE-2026-1699 (pwn request in preview.yml) — snapshot of eclipse-theia/theia-website (github_poc): https://github.com/pvharmo2/gha-lab-b5c1313658

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-1699 and fix it if it is affected.

What it is: CVE-2026-1699 is a critical code injection vulnerability in Eclipse Theia - Website, published on 30 Jan 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-2026-1699 exists.

Affected product: Eclipse Theia - Website. 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-2026-1699/ (Markdown: https://insights.sbomify.com/CVE-2026-1699/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-1699
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-1699
- OSV: https://osv.dev/vulnerability/CVE-2026-1699

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-1699/
Summaries are generated and may contain mistakes; the official description above is the record.