Cyber Resilience

CVE-2026-34450

LPE in Anthropic Claude Sdk For Python 0.86.0 – 0.87.0

Published
31 March 2026
Modified
24 July 2026
Patch / advisory
CVSS Score v4 4.8
Click a component to see what it means
Raw vectorCVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0012 2th percentile
Risk Priority 24 floored blend · peak EPSS

Summary

CVE-2026-34450 is a medium-severity Incorrect Default Permissions (CWE-276) vulnerability in Anthropic Claude Sdk For Python. Its CVSS base score is 4.8 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Credentials In Files (T1552.001); ranked at the 2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

This vulnerability is AI-related — categorised as APIs and Models; in the Privacy and Disclosure risk domain.

The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and AC-6 (Least Privilege) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

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…

more

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.

CWE(s)

AI Security AnalysisAI

AI Category
APIs and Models
Risk Domain
Privacy and Disclosure
OWASP Top 10 for LLMs 2025
None mapped
Classification Reason
Matched keywords: anthropic, claude

Related Threats

MITRE ATT&CK Enterprise Techniques

T1552.001 Credentials In Files Credential Access
Adversaries may search local file systems and remote file shares for files containing insecurely stored credentials.
T1552.004 Private Keys Credential Access
Adversaries may search for private key certificate files on compromised systems for insecurely stored credentials.
T1574.005 Executable Installer File Permissions Weakness Stealth
Adversaries may execute their own malicious payloads by hijacking the binaries used by an installer.
T1574.010 Services File Permissions Weakness Stealth
Adversaries may execute their own malicious payloads by hijacking the binaries used by services.
T1505.005 Terminal Services DLL Persistence
Adversaries may abuse components of Terminal Services to enable persistent access to systems.
T1548 Abuse Elevation Control Mechanism Privilege Escalation
Adversaries may circumvent mechanisms designed to control privilege elevation to gain higher-level permissions.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-34452Same product: Anthropic Claude Sdk For Python
CVE-2026-41686Same vendor: Anthropic
CVE-2026-34451Same vendor: Anthropic
CVE-2026-2915Shared CWE-276, CWE-732
CVE-2026-21765Shared CWE-276, CWE-732
CVE-2026-46406Same vendor: Anthropic
CVE-2026-54316Same vendor: Anthropic
CVE-2026-25725Same vendor: Anthropic
CVE-2026-25724Same vendor: Anthropic
CVE-2026-21852Same vendor: Anthropic

Affected Assets

anthropic
claude sdk for python
0.86.0 — 0.87.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 18 hardening rules · 4 OS baselines
Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

Enforces the access control policy that defines permissions on resources, thereby stopping incorrect assignments from remaining exploitable.

Requires least-privilege defaults so that installed files are not world-writable by default.

Requires documented, restrictive configuration settings that cover file and directory permissions.

Enforces access restrictions on changes, including permission settings applied during installation or configuration.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-05 full match
prevents

Directly requires defining, enforcing, and reviewing access permissions and least privilege on resources.

PR.PS-01 full match
prevents

Hardened baselines and configuration management explicitly require correct default file permissions.

ID.AM-08 partial match
prevents

Lifecycle management can encompass permission settings, yet the control is too broad to specifically mitigate incorrect defaults.

PR.PS-06 partial match
prevents

Secure SDLC practices include establishing secure defaults, but address only the development-phase portion of the weakness.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

By requiring owners to determine and document the exact permissions needed for each asset, the control reduces the likelihood that default or overly permissive file and resource permissions will be left in place.

prevents

Documented provisioning and revocation procedures reduce the chance that critical resources retain overly permissive default or leftover permissions after personnel changes.

prevents

Documented authorization, expiry rules, and audit logging of privileged accounts make it harder for critical resources to retain overly permissive or stale permission assignments.

prevents

Requiring explicit configuration of access controls and permissions for files, applications and services counters the assignment of overly permissive default or incorrect file-system rights.

prevents

Enforcing differentiated permissions on the source-code repository and program listings stops the assignment of overly broad default or inherited permissions to critical resources.

prevents

Standard templates that restrict access to utility programs and host parameter settings prevent the assignment of overly permissive default permissions on critical resources.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (1 rule)
  • V-248577 OL 8 must enable kernel parameters to enforce Discretionary Access Control (DAC) on symlinks. prevents CWE-732
Windows Server 2016 (4 rules)
  • V-224972 Active Directory Group Policy objects must have proper access control permissions. prevents CWE-732
  • V-224833 Permissions for program file directories must conform to minimum requirements. prevents CWE-276
  • V-224834 Permissions for the Windows installation directory must conform to minimum requirements. prevents CWE-276
Windows Server 2019 (4 rules)
  • V-205741 Windows Server 2019 Active Directory Group Policy objects must have proper access control permissions. prevents CWE-732
  • V-205735 Windows Server 2019 permissions for program file directories must conform to minimum requirements. prevents CWE-276
  • V-205736 Windows Server 2019 permissions for the Windows installation directory must conform to minimum requirements. prevents CWE-276
Windows Server 2022 (4 rules)
  • V-254393 Windows Server 2022 Active Directory Group Policy objects must have proper access control permissions. prevents CWE-732
  • V-254252 Windows Server 2022 permissions for program file directories must conform to minimum requirements. prevents CWE-276
  • V-254253 Windows Server 2022 permissions for the Windows installation directory must conform to minimum requirements. prevents CWE-276

References