CVE-2026-55607: Claude Code is an agentic coding tool

Q: How do I fix CVE-2026-55607?

claude code: upgrade to 2.1.163. Exact commands for each OS are on this page.

Q: Is CVE-2026-55607 being exploited?

CVE-2026-55607 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-55607 affect?

CVE-2026-55607 affects claude code. Severity is high (CVSS 8.8). Claude Code is an agentic coding tool. From 2.1.38 until 2.1.163, Claude Code's worktree handling allowed creation of worktrees named ".git" and navigation to worktrees outside the sandbox context, enabling git directory confusion attacks.

This month

HIGH 8.8UPGRADE

CVE-2026-55607 is a high-severity flaw (CVSS 8.8) affecting claude code. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Claude Code is an agentic coding tool. From 2.1.38 until 2.1.163, Claude Code's worktree handling allowed creation of worktrees named ".git" and navigation to worktrees outside the sandbox context, enabling git directory confusion attacks. By exploiting symlink manipulation and git fsmonitor execution during worktree operations, an attacker could overwrite files in the user's home directory (such as .zshenv), leading to code execution outside of

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.7% (top 48%)
CISA exploited list	No
Weakness	CWE-22, CWE-59, CWE-78
Published	2026-06-29
Last modified	2026-10-25

Publisher (CNA): GitHub, Inc. · Vendor: anthropic

Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-29 15:16 UTCPublished CVE record published
2026-10-25 21:10 UTCUpdated Record last modified

anthropic claude code UPGRADE

Affected: >= 2.1.38 and < 2.1.163

Fixed in: 2.1.163

Safe to downgrade to: a release before 2.1.38

1. Check installed version

npm ls claude-code

2. UPGRADE to 2.1.163

npm install claude-code@">=2.1.163"

3. If no update is available yet, DOWNGRADE to a release before 2.1.38

npm view claude-code versions npm install claude-code@"<2.1.38"

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-55607?

claude code: upgrade to 2.1.163. Exact commands for each OS are on this page.

Is CVE-2026-55607 being exploited?

CVE-2026-55607 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-55607 affect?

CVE-2026-55607 affects claude code. Severity is high (CVSS 8.8). Claude Code is an agentic coding tool. From 2.1.38 until 2.1.163, Claude Code's worktree handling allowed creation of worktrees named ".git" and navigation to worktrees outside the sandbox context, enabling git directory confusion attacks.

How urgent is CVE-2026-55607?

Priority 44/100. High severity

Software pages

Git vulnerabilities

Related CVEs

CVE-2026-54316 CRITICAL 9.1 UPGRADE Claude Code is an agentic coding tool
CVE-2026-46406 MEDIUM 6.1 UPGRADE Claude Code is an agentic coding tool

References

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