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GitHub confirmed that attackers exfiltrated about 3,800 internal repositories after compromising an employee device with a trojanized Visual Studio Code extension, later identified in multiple reports as Nx Console 18.95.0. The company said the malicious extension was removed, the affected endpoint was isolated, critical secrets and credentials were rotated, and incident response, log analysis, and follow-on monitoring were launched. GitHub’s current assessment is that the intrusion was limited to GitHub-internal repositories, with no evidence that customer repositories, enterprise accounts, or data stored outside those repositories were broadly affected, though some internal repositories may contain limited customer-related support information.
The breach was widely attributed to TeamPCP (also tracked as UNC6780), which advertised the stolen source code and internal organizational data on cybercrime forums and leak sites for $50,000 to $95,000, threatening to publish it if unsold. Reporting tied the compromise to the broader TanStack supply-chain campaign and said the poisoned extension was briefly available on Visual Studio Marketplace and OpenVSX, carrying credential-stealing malware aimed at GitHub, npm, AWS, Kubernetes, 1Password, and other developer assets. GitHub later told GitHub Enterprise Server administrators to rotate GPG public keys as part of signing-key rotation, while government and industry alerts urged organizations to remove the malicious extension, rotate exposed developer credentials, and scrutinize CI/CD and repository activity for follow-on abuse.
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Canada's Cyber Centre published Alert AL26-013 about the GitHub incident, stating GitHub detected the intrusion on May 18 and attributing initial access to Nx Console version 18.95.0 on a compromised employee device. The alert advised removing the extension, rotating exposed credentials from the May 11–20 window, monitoring CI/CD activity, and following GitHub Enterprise Server key-rotation guidance.
GitHub told administrators of self-hosted GitHub Enterprise Server environments to rotate public encryption keys following the incident. The guidance reiterated that GitHub was rotating all keys, including the Enterprise Server signing key, while saying no evidence showed customer or enterprise repositories were compromised.
FINRA warned member firms about downstream risks from the GitHub breach and summarized GitHub's May 20 confirmation that about 3,800 internal repositories were affected. The alert urged increased monitoring, compensating controls, employee training, and reporting of suspicious activity to regulators and law enforcement.
Follow-up reporting said GitHub linked the breach to a malicious version of the Nx Console VS Code extension, tracing the compromise to the broader TanStack-related supply-chain attack. Reports also said the extension carried credential-stealing functionality targeting developer and cloud secrets.
GitHub published an investigation update requiring GitHub Enterprise Server administrators to rotate GPG public keys because the company was rotating keys, including the GitHub Enterprise Server signing key, as a precaution. GitHub Enterprise Cloud customers were told no action was required.
GitHub disclosed that attackers exfiltrated about 3,800 internal repositories after compromising an employee device through a poisoned Visual Studio Code extension. The company said its assessment indicated the activity was limited to GitHub-internal repositories and that it had no evidence customer data stored outside those repositories was affected.
After detecting the compromise, GitHub isolated the affected endpoint, removed the malicious extension version, launched incident response, and began rotating critical secrets and credentials. Some reporting specifies that secret rotation started Monday into Tuesday following discovery.
TeamPCP claimed on Breached/BreachForums that it had stolen roughly 4,000 private GitHub repositories, source code, and internal organizational data, offering the data for sale and threatening to leak it if unsold. One report explicitly dates the forum advertisement to May 19, 2026.
GitHub detected unauthorized access after a compromised employee device, infected via a malicious VS Code extension, was used to access and exfiltrate roughly 3,800 internal repositories. Multiple reports state the incident was detected on May 18 or May 19, with GitHub later tying the intrusion to its internal repositories only.
A trojanized Nx Console Visual Studio Code extension, version 18.95.0, was made available on Visual Studio Marketplace and OpenVSX for about 18 minutes. Reporting says this poisoned extension was the initial infection vector used against a GitHub employee device.
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GitHub confirmed that an attacker accessed internal repositories after a malicious Visual Studio Code extension was installed on an employee device, leading to the exfiltration of roughly **3,800 GitHub-internal repositories**. GitHub said it detected and contained the intrusion, removed the malicious extension version, and isolated the affected endpoint. Independent analysis of a leaked file list reportedly found **3,874 unique** `.tar.gz` archive names, broadly matching GitHub’s estimate of the stolen data. The exposed repositories reportedly include projects tied to **security tooling, identity systems, CI/CD, infrastructure-as-code, GitHub Actions, Terraform, certificates, and Copilot-related work**, increasing the risk of follow-on supply-chain abuse and targeted social engineering. The threat actor, using the alias **TeamPCP**, is said to be offering the dataset for sale on an underground forum for more than **$50,000**, raising concerns that internal code and operational details could be weaponized against GitHub and its customers.
Jul 12, 2026
A malicious `18.95.0` release of the **Nx Console** VS Code extension was briefly published to the Visual Studio Marketplace after attackers used stolen GitHub and marketplace publishing credentials to push a tampered build outside the normal release pipeline. The extension fetched an obfuscated payload from an orphaned commit in the official `nrwl/nx` GitHub repository and executed it when a workspace was opened, turning the trusted developer tool into a credential stealer. Researchers and vendor advisories said the malware harvested secrets from GitHub, npm, AWS, HashiCorp Vault, Kubernetes, 1Password, local files, and Claude Code-related configuration, then exfiltrated data over HTTPS, the GitHub API, and DNS while using anti-analysis checks and avoiding some CIS-region systems. The intrusion was tracked as **`CVE-2026-48027`** and was described as a supply-chain attack aimed at developer workstations rather than production servers directly, with the likely objective of pivoting into repositories, CI/CD pipelines, package registries, and cloud infrastructure through stolen trust material. Reports said the payload also attempted persistence on macOS and Linux and included Sigstore, Fulcio, and SLSA-related logic that could help attackers publish packages with apparently valid signed provenance using stolen OIDC tokens. Nx removed the malicious release, revoked exposed credentials, added stricter release approvals, and told users who installed `18.95.0` and opened a workspace during the exposure window to upgrade to `18.100.0` or later, remove persistence artifacts, terminate malicious processes, rotate all reachable credentials, and audit repositories, workflows, and service-account activity for abuse.
Jun 29, 2026
Security researchers reported multiple attack paths in **GitHub Codespaces** where opening a malicious repository or pull request can trigger **remote code execution (RCE)** by abusing repository-controlled **VS Code configuration** that Codespaces automatically honors (e.g., `.vscode/` and `.devcontainer/`). The described impact includes arbitrary command execution inside the Codespace, **exfiltration of GitHub tokens and secrets**, and abuse of hidden APIs to access premium **Copilot** models—highlighting developer environments as a high-value supply-chain entry point because they often contain credentials outside centralized secret management. In parallel, the **Eclipse Foundation** announced it will mandate **pre-publish security checks** for extensions uploaded to the *Open VSX Registry* to reduce supply-chain risk from malicious or compromised extensions. The planned controls aim to detect and quarantine suspicious uploads (e.g., **namespace/name impersonation**, accidentally published secrets, and known malicious patterns) before they are publicly available, following a trend of increased attacks on extension/package ecosystems (including recent cases where a **compromised publisher account** was used to ship poisoned updates).
Jun 29, 2026