Local state disclosure and tampering via permissive modes
Published May 4, 2026 · Updated May 4, 2026
Incorrect file permissions in Anthropic TypeScript SDK 0.79.0 through 0.91.0 allow local users to read or alter persisted agent state. The BetaLocalFilesystemMemoryTool creates memory files with mode 0o666 and directories with mode 0o777, relying on the process umask rather than restricting access. On a shared host this exposes state to other local accounts; with a permissive umask, including affected container deployments, those accounts can modify state and influence later model behavior.
Summary
What happened
Incorrect file permissions in Anthropic TypeScript SDK 0.79.0 through 0.91.0 allow local users to read or alter persisted agent state. The BetaLocalFilesystemMemoryTool creates memory files with mode 0o666 and directories with mode 0o777, relying on the process umask rather than restricting access. On a shared host this exposes state to other local accounts; with a permissive umask, including affected container deployments, those accounts can modify state and influence later model behavior.
The record
- CVE
- CVE-2026-41686
- Published
- May 4, 2026
- Updated
- May 4, 2026
- Vendor
- Anthropic
- Product
- Anthropic TypeScript SDK
- Classifications
- CWE-732, T1005, T1565.001
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 4, 2026CVE publishedPublication date reported by the CVE source.
- May 4, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>= 0.79.0, < 0.91.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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