# CVE-2026-34450: Claude SDK for Python: Insecure Default File Permissions in Local Filesystem Memory Tool

> Local attackers can read or modify agent memory files due to insecure default permissions in the Anthropic Python SDK.

- **Severity:** Medium 4.8 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 31 Mar 2026
- **Updated:** 1 Apr 2026
- **Also known as:** ECHO-3bbc-736a-5aa2, GHSA-q5f5-3gjm-7mfm, PYSEC-2026-2114

## What is CVE-2026-34450?

CVE-2026-34450 is a medium-severity vulnerability in anthropics anthropic-sdk-python, published on 31 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### 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 local filesystem memory tool in the Anthropic Python SDK created memory files with mode 0o666, leaving them world-readable on systems with a standard umask and world-writable in environments with a permissive umask such as many Docker base images. A local attacker on a shared host could read persisted agent state, and in containerized deployments could modify memory files to influence subsequent model behavior. Both the synchronous and asynchronous memory tool implementations were affected. This issue has been patched in version 0.87.0.

Weakness: CWE-732 (Incorrect Permission Assignment for Critical Resource), CWE-276 (Incorrect Default Permissions)

## Which versions are affected by CVE-2026-34450?

3 open source packages ship an affected version, including anthropic. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `anthropic` | PyPI | From 0.86.0 | 0.87.0 |
| `anthropic` | PyPI | From 0.86.0 | 0.87.0 |
| `anthropic` | PyPI | From 0.86.0 | 0.87.0 |

Products: Anthropic Claude Sdk for Python.

## How do I fix CVE-2026-34450?

Upgrade anthropic to 0.87.0 or later.

## Is CVE-2026-34450 being exploited?

There is no known exploitation of CVE-2026-34450 in the wild and no public exploit code.

## Other vulnerabilities in anthropics anthropic-sdk-python

- [CVE-2026-34452](https://insights.sbomify.com/CVE-2026-34452/): Claude SDK for Python: Memory Tool Path Validation Race Condition Allows Sandbox Escape (medium 5.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-34450 and fix it if it is affected.

What it is: CVE-2026-34450 is a medium-severity vulnerability in anthropics anthropic-sdk-python, published on 31 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-34450 in the wild and no public exploit code.

Affected packages and fixed versions:
- anthropic (PyPI): affected from 0.86.0; fixed in 0.87.0
- anthropic (PyPI): affected from 0.86.0; fixed in 0.87.0
- anthropic (PyPI): affected from 0.86.0; fixed in 0.87.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-34450/ (Markdown: https://insights.sbomify.com/CVE-2026-34450/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-34450
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-34450
- OSV: https://osv.dev/vulnerability/CVE-2026-34450

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-34450/
Summaries are generated and may contain mistakes; the official description above is the record.