How severe is CVE-2026-88968?

No CVSS score has been assigned to CVE-2026-88968 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-88968?

CVE-2026-88968 affects the following packages: @anthropic-ai/claude-code (npm). Ecosystems affected: npm.

How do I fix CVE-2026-88968?

Update @anthropic-ai/claude-code to 2.1.251 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-88968 is resolved across your whole dependency graph.

How do I detect CVE-2026-88968 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @anthropic-ai/claude-code, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-88968 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2026-88968 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-88968 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-88968?

CVE-2026-88968 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 25th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-88968?

CVE-2026-88968 is classified as CWE-59 (CWE-59), CWE-367 (CWE-367). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-88968 published, and has it been updated?

CVE-2026-88968 was published on November 3, 2026 and was last updated on November 5, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2026-88968: @anthropic-ai/claude

Exploitation Status

No confirmed exploitation observed yet

A successful exploit gives an attacker total control of the affected component, not partial access.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-88968.

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs25th percentile — riskier than 25% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

281other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

@anthropic-ai/claude-codenpm

15.3Mdownloads / week

Description

Claude Code validated Edit tool targets using point-in-time pathname and symlink resolution that was not bound to the underlying directory inodes or file descriptors. On macOS, a process running inside Claude Code's Bash sandbox could exploit the resulting time-of-check to time-of-use window by atomically swapping an in-workspace parent directory with a symlink after validation completed, causing the unsandboxed Edit implementation to overwrite an attacker-selected user-writable file outside the workspace. Exploiting this required the ability to run attacker-controlled code inside the sandbox, such as through a malicious repository or dependency script.

Users on standard Claude Code auto-update have received this fix automatically. Users performing manual updates are advised to update to the latest version.

Claude Code thanks hackerone.com/mahoraga007 (Sunder Singh) for reporting this issue.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`@anthropic-ai/claude-code`	all versions	2.1.251`npm install @anthropic-ai/claude-code@2.1.251`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @anthropic-ai/claude-code, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @anthropic-ai/claude-code to 2.1.251 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-88968 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatImportant

This vulnerability is rated as Important because successful exploitation permits escaping the execution sandbox and writing arbitrary host files, which compromises system integrity. Within containerized developer platforms such as Red Hat OpenShift Dev Spaces, triggering the flaw requires an attacker to convince a…

Workaround published by Red Hat

--- CME Mitigation Guidance (2026-11-04) --- Disclaimer: The following mitigation solutions are provided as a courtesy, pending the application of an official patch. This content was generated utilizing AI tools in conjunction with data from https://cmetaxonomy.org. Customers are advised to independently evaluate and test these temporary mitigations within their own infrastructure. The highest-value action is to bind file tool path validation to directory inodes or open file descriptors to prevent file operations from resolving symlinks outside the workspace: upgrade to Claude Code 2.1.251 (or the fixed Devspaces/Pluginregistry Rhel builds), which prevent file tools (Read, Write, Edit) from…

Source: Red Hat security advisory for CVE-2026-88968 (CC BY 4.0)

Frequently Asked Questions

Claude Code validated Edit tool targets using point-in-time pathname and symlink resolution that was not bound to the underlying directory inodes or file descriptors. On macOS, a process running inside Claude Code's Bash sandbox could exploit the resulting time-of-check to time-of-use window by atomically swapping an in-workspace parent directory with a symlink after validation completed, causing the unsandboxed Edit implementation to overwrite an attacker-selected user-writable file outside the workspace. Exploiting this required the ability to run attacker-controlled code inside the sandbox,

O3 Security · Impact-Aware SCA

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CVE-2026-88968 — @anthropic-ai/claude-code