Researchers at Novee disclosed Cordyceps, a systemic class of weaknesses in CI/CD pipelines, especially GitHub Actions workflows, that lets an attacker with nothing more than a free account hijack a project's build and release process. The danger is not a single bug but how workflows chain together: an untrusted pull request or comment feeds a low-privilege workflow whose output flows into a higher-privilege one, ending in stolen credentials, poisoned artifacts, or malicious releases. A scan of 30,000 repositories found over 300 fully exploitable, with fixes confirmed by Microsoft, Google, Apache, Cloudflare, and the Python Software Foundation. Standard scanners miss it because they check files in isolation.
Researcher RyotaK has disclosed a now-patched flaw in Anthropic's Claude Code GitHub Action, which drops Claude into CI/CD to triage issues and review PRs with broad repo permissions. The action's trigger check waved through any actor whose name ended in [bot] - but anyone can register a GitHub App and use its token to open an issue on a public repo. Agent mode lacked the human-actor check tag mode had. The attacker then used indirect prompt injection in an issue to make Claude read /proc/self/environ and write back the OIDC credentials, which can be replayed for an installation token with write access. Anthropic's example workflow shipped with allowed_non_write_users: '*'.
SafeDep has detailed Megalodon, a GitHub Actions attack that scans 5,561 repositories for usable CI/CD secrets and credentials by submitting malicious pull requests that contain crafted workflow files. The campaign appears unrelated to the recent TeamPCP supply-chain wave. Separately, a throwaway npm account 'polymarketdev' published nine packages within 30 seconds (polymarket-trading-cli, polymarket-terminal, polymarket-trade, polymarket-auto-trade, polymarket-copy-trading, polymarket-bot, polymarket-claude-code, polymarket-ai-agent, polymarket-trader) that, on postinstall, present a fake wallet onboarding prompt and exfiltrate Ethereum and Polygon private keys to a Cloudflare Worker at polymarketbot.polymarketdev.workers[.]dev. The malicious packages remain live on npm at time of publication.
Between 01:56 and 02:56 UTC on May 19, a Shai-Hulud-flavored attack published 639 malicious versions across 323 npm packages, mostly in the @antv chart and graph namespace, after compromising the maintainer account 'atool.' Affected libraries include @antv/g2, @antv/g6, echarts-for-react, timeago.js, and jest-canvas-mock (still 10M monthly downloads despite three years dormant). A linked attack hijacked 15 tags of the 'actions-cool' GitHub Action and replaced them with a credential stealer that reads runner memory and exfils to t.m-kosche[.]com - the same domain as the @antv campaign. Socket and Aikido say there are now 2,900+ GitHub repos generated by this wave.