CVE-2026-45539: Microsoft APM improper link resolution in apm-cli

CVE-2026-45539 · Severity: high · CVSS 7.4 · Published 2026-05-15

Microsoft APM is a tool used to manage dependencies for AI agents. A security flaw allows a malicious package to include symbolic links that, when installed, trick the tool into copying sensitive files from the user's local computer into the project directory. These stolen files may then be accidentally committed to public code repositories, leading to the exposure of private data or credentials.

Technologies: Microsoft Apm-Cli. Vendors: Microsoft, PyPI.

Quick answers

Is CVE-2026-45539 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-45539 being exploited in the wild.
How severe is CVE-2026-45539?
High severity, with a CVSS score of 7.4, published 15 May 2026.
Which products and versions are affected?
Microsoft Apm-Cli 0.5.4 to 0.12.4; apm (PyPI) >= 0.5.4, <= 0.12.4, ECOSYSTEM:introduced=0.5.4,fixed=0.13.0.
Is there a fix for CVE-2026-45539?
Yes. apm (PyPI): upgrade to 0.13.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-45539 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-45539?
Check whether you run Microsoft Apm-Cli or apm (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • apm (PyPI): upgrade to 0.13.0 or later
    pip install "apm>=0.13.0"

Technical details

The apm-cli component in Microsoft APM versions 0.5.4 through 0.12.4 contains a vulnerability where the 'PromptIntegrator' and 'AgentIntegrator' classes use Path.glob() and Path.read_text() without verifying if the target is a symbolic link. When a user installs a malicious dependency, the tool preserves symlinks in the 'apm_modules/' directory and subsequently dereferences them during the integration phase. This causes the contents of the linked local files (outside the package root) to be written as regular files into the project's deployment directories (e.g., .github/prompts/, .claude/agents/). Because these deployment directories are typically not included in the auto-generated .gitignore, the exfiltrated data is likely to be staged and committed by the user. The vulnerability is fixed in version 0.13.0.

Affected products

  • Microsoft apm-cli 0.5.4 to 0.12.4

Identifiers

  • CVE-2026-45539
  • GHSA-q5pp-gvjg-h7v4
  • PYSEC-2026-2377

Timeline

  • 2026-05-11: advisory: GitHub Security Advisory published
  • 2026-05-15: disclosed: CVE published to NVD

References

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