Information disclosure in Microsoft Apm

CVE-2026-45539

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.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.011 (63.1th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 63rd percentile — 63.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-45539: held from 0.007 to 0.011.

EPSS over last 30 days · oldest: 0.007 · newest: 0.011 · change: +0.004

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-45539?
CVE-2026-45539 is a high-severity vulnerability in Microsoft Apm, classified under Improper Link Resolution Before File Access. CVSS score: 7.4/10. Published 2026-05-15.
How severe is CVE-2026-45539?
High severity. CVSS v3 base score is 7.4 out of 10.