Eclipse Theia Website CI Executes Untrusted PR Code via pull_request_target
CVE-2026-1699 Published on January 30, 2026

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.

NVD

Vulnerability Analysis

CVE-2026-1699 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. An automatable proof of concept (POC) exploit exists. The potential impact of an exploit of this vulnerability is considered to be critical as this vulnerability has a high impact to the confidentiality, integrity and availability of this component.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
CHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
HIGH

Weakness Type

Inclusion of Functionality from Untrusted Control Sphere

The software imports, requires, or includes executable functionality (such as a library) from a source that is outside of the intended control sphere.


Affected Versions

Eclipse Foundation Eclipse Theia - Website:

Exploit Probability

EPSS
0.04%
Percentile
11.10%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.