CVE-2026-44359

Meshtastic is an open source mesh networking solution. Prior to version 2.7.21.1370b23, the Meshtastic GitHub repository's mainmatrix.yml workflow is triggered by pullrequesttarget  and multiple jobs check out the attacker's fork code and execute it with access to repository secrets and elevated GITHUBTOKEN permissions. No approval gate exists. Pull requests from external users with authorassociation: "NONE" triggered the CI workflow automatically. The workflow directly executes attacker-controlled files from the fork checkout. This issue could have resulted in supply chain compromise, self-hosted runner compromise, and/or repository takeover for the repo. This issue is separate from GHSA-6mwm-v2vv-pp96, which addressed a command injection via github.headref in the setup job of the same workflow. That fix correctly moved to environment variables. However, the more critical fork checkout vulnerability across the check, build, and build-debian-src jobs was not addressed. Version 2.7.21.1370b23 contains a patch for thie issue.