AnthropicGHSA-5474-4w2j-mq4c
Memory Tool Path Validation Allows Sandbox Escape to Sibling Directories
Medium6.3CVE-2026-34451 · Published Mar 31, 2026
The local filesystem memory tool in the Anthropic TypeScript SDK validated model-supplied paths using a string prefix check that did not append a trailing path separator. A model steered by prompt injection could supply a crafted path that resolved to a sibling directory sharing the memory root's name as a prefix, allowing reads and writes outside the sandboxed memory directory. Users on the affected versions are advised to update to the latest version. Thank you to hackerone.com/nicksim for reporting this issue!
Affected versions
| Package | Affected | Fixed in |
|---|---|---|
| @anthropic-ai/sdk npm | >= 0.79.0, < 0.81.0 | 0.81.0 |
Details and references
More Anthropic advisories
All Anthropic| Date | Advisory | Severity | Fixed in |
|---|---|---|---|
| Apr 24 | Trust Dialog Bypass via Git Worktree Spoofing Allows Arbitrary Code Execution | High7.7 | 2.1.84 |
| Apr 20 | Sandbox Escape via Symlink Following Allows Arbitrary File Write Outside Workspace | High7.7 | 2.1.64 |
| Apr 17 | Insecure System-Wide Configuration Loading Enables Local Privilege Escalation on Windows | Medium5.4 | 2.1.75 |
| Mar 31 | Memory Tool Path Validation Race Condition Allows Sandbox Escape | Medium5.8 | 0.87.0 |
| Mar 31 | Insecure Default File Permissions in Local Filesystem Memory Tool | Medium4.8 | 0.87.0 |
| Mar 18 | Workspace Trust Dialog Bypass via Repo-Controlled Settings File | High7.7 | 2.1.53 |