Time-of-check Time-of-use (TOCTOU) Race Condition Affecting anthropic package, versions [0.86.0,0.87.0)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published5 Apr 2026
- disclosed1 Apr 2026
- creditUnknown
Introduced: 1 Apr 2026
CVE-2026-34452 (opens in a new tab)How to fix?
Upgrade anthropic to version 0.87.0 or higher.
Overview
anthropic is a The official Python library for the anthropic API
Affected versions of this package are vulnerable to Time-of-check Time-of-use (TOCTOU) Race Condition via the _validate_path function in the _beta_builtin_memory_tool.py file. An attacker can access files outside the intended sandbox directory by exploiting a race condition between path validation and file operation, allowing reads or writes to escape the sandbox. This is only exploitable if a local attacker is able to write to the memory directory.