CVE-2025-65099: anthropics claude-code · Code Injection
Affects anthropics claude-codeSource CVE Database V5
Not known to be exploited · CVSS 7.7 High : upgrade to 1.0.39 soon.
Data as of 25 Oct 2026, 19:02 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 45% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.0.39
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 19 Nov 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.
What to do
Upgrade anthropics/claude-code to 1.0.39.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
npmanthropics/claude-codepkg:npm/anthropics/claude-codeOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
European organizations should immediately upgrade anthropics Claude Code to version 1.0.39 or later to eliminate this vulnerability. Until upgrading is complete, developers must avoid launching Claude Code in untrusted or unknown project directories, especially those containing Yarn plugins. Implement strict access controls and monitoring on development environments to detect unusual execution patterns or unauthorized code execution. Educate developers about the risks of opening untrusted projects and the importance of verifying the source of Yarn plugins. Employ endpoint detection and response (EDR) solutions capable of identifying suspicious process behaviors related to code injection. Integrate software composition analysis tools to monitor dependencies and plugins for malicious content. Additionally, consider sandboxing development environments or using virtual machines to isolate potentially risky operations. Regularly review and update security policies governing development tools and workflows to incorporate lessons learned from this vulnerability.
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.