Vulnerability · Published Mar 31, 2026 · Assigned by GitHub_M
CVE-2026-34452Claude SDK for Python: Memory Tool Path Validation Race Condition Allows Sandbox Escape
Medium 5.8
In plain English
A medium-severity security flaw in anthropic-sdk-python from anthropics. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 4% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
The Claude SDK for Python provides access to the Claude API from Python applications. From version 0.86.0 to before version 0.87.0, the async local filesystem memory tool in the Anthropic Python SDK validated that model-supplied paths resolved inside the sandboxed memory directory, but then returned the unresolved path for subsequent file operations. A local attacker able to write to the memory directory could retarget a symlink between validation and use, causing reads or writes to escape the sandbox. The synchronous memory tool implementation was not affected. This issue has been patched in version 0.87.0.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | anthropic | 0.87.0 | GHSA-w828-4qhx-vxx3 |
| PyPI | anthropic | 0.87.0 | PYSEC-2026-2115 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| anthropics | anthropic-sdk-python | >= 0.86.0, < 0.87.0 |
Weakness: CWE-59, CWE-367 · Vector: CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N
References
- https://github.com/anthropics/anthropic-sdk-python/security/advisories/GHSA-w828-4qhx-vxx3 x_refsource_CONFIRM
- https://github.com/anthropics/anthropic-sdk-python/commit/6599043eee6e86dce16953fcd1fd828052052be6 x_refsource_MISC
- https://github.com/anthropics/anthropic-sdk-python/releases/tag/v0.87.0 x_refsource_MISC