CVE-2026-25725
criticalpriority · track · 40EPSS 0.005 · 45 %ileEUUSEPSS · scored 2026-10-27
Claude Code is an agentic coding tool. Prior to version 2.1.2, Claude Code's bubblewrap sandboxing mechanism failed to properly protect the .claude/settings.json configuration file when it did not exist at startup. While the parent directory was mounted as writable and .claude/settings.local.json was explicitly protected with read-only constraints, settings.json was not protected if it was missing. This allowed malicious code running inside the sandbox to create this file and inject persistent hooks (such as SessionStart commands) that would execute with host privileges when Claude Code was restarted. This issue has been patched in version 2.1.2.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–critical · 5.2–10
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (3)
Products and version ranges known to be affected.
advisories (1)
Vendor and ecosystem advisories describing this.
- GHSA-ff64-7w26-62rfClaude Code has Sandbox Escape via Persistent Configuration Injection in settings.json2026-02-06ghsa · osvUS
Claude Code's bubblewrap sandboxing mechanism failed to properly protect the .claude/settings.json configuration file when it did not exist at startup. While the parent directory was mounted as writable and .claude/settings.local.json was explicitly protected with read-only constraints, settings.json was not protected if it was missing. This allowed malicious code running inside the sandbox to create this file and inject persistent hooks (such as SessionStart commands) that would execute with host privileges when Claude Code was restarted. Users on standard Claude Code auto-update received this fix automatically. Users performing manual updates are advised to update to the latest version. Claude Code thanks hackerone.com/edbr for reporting this issue!
also known as (3)
Other names and identifiers for this entity.
sources
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references (4)
External citations — patches, advisories, analysis.
- https://github.com/anthropics/claude-code/security/advisories/GHSA-ff64-7w26-62rfcnnvd
- https://github.com/anthropics/claude-code/tagsPatchcnnvd
- https://github.com/anthropics/claude-code/security/advisories/GHSA-ff64-7w26-62rfenisa_euvd
- https://github.com/anthropics/claude-code/security/advisories/GHSA-ff64-7w26-62rfThird Party Advisorynvd
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