---
title: "CVE-2026-86063: Claude Code: Plugin Hash Pin Bypass Allows Bypass of Hash Pinning"
url: https://erroneo.us/security/cve/CVE-2026-86063/
description: "CVE-2026-86063 (anthropics claude-code): Claude Code is an agentic coding tool. Prior to 2.1.179, the Claude Code and Claude Desktop plugin installation…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-10-13
date_modified: 2026-10-21
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-86063"
kev: false
cvss: 7.5
epss: 0.00171
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-86063: Claude Code: Plugin Hash Pin Bypass Allows Bypass of Hash Pinning

**Signal:** Normal patch cycle. No exploitation signal; fix it in your next routine update if you are affected. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.2% , percentile 6: FIRST’s model estimates a 0.2% chance of exploitation activity in the next 30 days, higher than 6% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Editorial verdict: Check exposure. Plugin4Shell: Plugin Pin Bypass in AI Coding Agents — Claude Code and Codex users on current versions are fixed; the real exposure is Copilot or Gemini CLI plugins that auto-update from repositories hosted outside GitHub.

## What it is

Claude Code is an agentic coding tool. Prior to 2.1.179, the Claude Code and Claude Desktop plugin installation flow runs git checkout for a marketplace-pinned commit without verifying that the resulting HEAD equals the pinned 40-character SHA. An attacker who controls a plugin repository on a Git host that permits SHA-shaped branch names can create a branch named after the reviewed commit, causing checkout to select the branch tip and install attacker-controlled plugin code. Exploitation requires a user to install the malicious plugin and pin it to the ostensibly safe hash. This issue is fixed in version 2.1.179.

## Affected products (CVE record)

- anthropics claude-code: < 2.1.179

## Severity

- GitHub_M CVSS 4.0: 7.5 `CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.17% probability of exploitation activity in the next 30 days; percentile 6.

## Sources

- [CVE.org record CVE-2026-86063](https://www.cve.org/CVERecord?id=CVE-2026-86063)
- [NVD entry CVE-2026-86063](https://nvd.nist.gov/vuln/detail/CVE-2026-86063)
- [github.com](https://github.com/anthropics/claude-code/security/advisories/GHSA-pq7j-f95f-qfcv)
- [github.com](https://github.com/anthropics/claude-code/releases/tag/v2.1.179)

---
Source page: https://erroneo.us/security/cve/CVE-2026-86063/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt