high · 7.5 Patched

Claude Code: Plugin Hash Pin Bypass Allows Bypass of Hash Pinning

CVE-2026-86063 · GHSA-pq7j-f95f-qfcv · published 15 Oct 2026

How serious is it

  • Severity: high, CVSS score 7.5 out of 10.
  • No exploit prediction (EPSS) score yet.
  • Not on the CISA list of exploited vulnerabilities.
  • No public exploit in Exploit-DB.

Is your app affected by CVE-2026-86063?

Paste this prompt into Claude Code, Cursor or any AI coding tool: it runs a free Shippable scan of your project and fixes what it finds. Built with Lovable, Bolt or v0? Scan your live app. Or upload your package file.

Who is affected

  • @anthropic-ai/claude-code (npm) < 2.1.179

How to check

  1. Run npm ls @anthropic-ai/claude-code in your project to see the installed version, including copies pulled in by other packages.
  2. Or paste your lockfile into the checker: it lists every package with a known vulnerability, this one included.
  3. Or run npx shippable-dev scan localhost:3000 in your project folder. It reads your lockfile and flags this vulnerability along with every other known one.

How to fix

Copies a prompt for Claude Code, Cursor or Codex: it checks your lockfiles for this and upgrades it.
  1. Upgrade @anthropic-ai/claude-code to 2.1.179 or later, commit the lockfile and redeploy.
  2. If a vulnerable version was live, check your logs and rotate the secrets that server could read.

The advisory

The plugin install flow in Claude Code and Claude Desktop checked out a marketplace's pinned commit SHA using `git checkout` without verifying that the resulting HEAD matched the pinned SHA. An attacker controlling a plugin's upstream repository could create a branch named identically to the pinned 40-character SHA, causing the checkout to silently resolve to the attacker's branch tip instead of the reviewed commit, resulting in attacker-controlled code being installed bypassing the pinned hash. Exploitation required a user to install a malicious plugin, pin to a safe hash, and for the plugin source to be hosted on a git host that permitted SHA-shaped branch names. Users on standard Claude Code auto-update have received this fix already. Users performing manual updates are advised to update to the latest version. Thank you to Or Nevo Michrowski of Air Security for reporting this issue.

Check your whole app

Dependencies are only half of it. Free and read-only: before you push, run npx shippable-dev scan localhost:3000 in your project folder, no account needed. For your live app, you prove it's yours with a one-line tag first.

References

Merged from GitHub Advisory Database. Last updated 23 Oct 2026. All vulnerabilities · RSS · JSON

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