How severe is CVE-2025-65099?

CVE-2025-65099 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2025-65099 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (35th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-65099?

CVE-2025-65099 affects Anthropic Claude Code. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-65099?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2025-65099 have an EU (EUVD) identifier?

Yes. CVE-2025-65099 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-198179.

When was CVE-2025-65099 published?

CVE-2025-65099 was published on 2025-11-19 and last updated on 2026-06-17.

CVE-2025-65099

CVE-2025-65099 is a critical-severity vulnerability in Anthropic Claude Code with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-94.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v4: 7.7
EPSS exploit prediction: 0% (35th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-198179
Weakness: CWE-94
Affected product: Anthropic Claude Code
Published: 2025-11-19
Last modified: 2026-06-17

Description

Claude Code is an agentic coding tool. Prior to version 1.0.39, when running on a machine with Yarn 3.0 or above, Claude Code could have been tricked to execute code contained in a project via yarn plugins before the user accepted the startup trust dialog. Exploiting this would have required a user to start Claude Code in an untrusted directory and to be using Yarn 3.0 or above. This issue has been patched in version 1.0.39.

Frequently asked questions

What is CVE-2025-65099?: Claude Code is an agentic coding tool. Prior to version 1.0.39, when running on a machine with Yarn 3.0 or above, Claude Code could have been tricked to execute code contained in a project via yarn plugins before the user accepted the startup trust dialog. Exploiting this would have required a user to start Claude Code in an untrusted directory and to be using Yarn 3.0 or above. This issue has been patched in version 1.0.39.
How severe is CVE-2025-65099?: CVE-2025-65099 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2025-65099 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (35th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-65099?: CVE-2025-65099 affects Anthropic Claude Code. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-65099?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2025-65099 have an EU (EUVD) identifier?: Yes. CVE-2025-65099 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-198179.
When was CVE-2025-65099 published?: CVE-2025-65099 was published on 2025-11-19 and last updated on 2026-06-17.

References

https://github.com/anthropics/claude-code/security/advisories/GHSA-5hhx-v7f6-x7gv

Affected products (1)

cpe:2.3:a:anthropic:claude_code:*:*:*:*:*:node.js:*:*

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