CVE-2026-45539Public exploitNetwork attack vector

Host file disclosure via dependency symlink dereference

Published May 15, 2026 · Updated May 15, 2026

Link following in Microsoft APM 0.5.4 through 0.12.4 allows remote attackers to disclose host files via a malicious dependency. PromptIntegrator and AgentIntegrator enumerate untrusted package entries with Path.glob or Path.rglob and pass matches to Path.read_text without rejecting symlinks. Exploitation requires a user or automation to install the attacker's dependency; readable host content is copied into project-tracked deployment files.

CVSS severity7.4
High
EPSS probability0.65%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Link following in Microsoft APM 0.5.4 through 0.12.4 allows remote attackers to disclose host files via a malicious dependency. PromptIntegrator and AgentIntegrator enumerate untrusted package entries with Path.glob or Path.rglob and pass matches to Path.read_text without rejecting symlinks. Exploitation requires a user or automation to install the attacker's dependency; readable host content is copied into project-tracked deployment files.

The record

CVE
CVE-2026-45539
Published
May 15, 2026
Updated
May 15, 2026
Vendor
Microsoft
Product
APM
Classifications
CWE-200, CWE-59, T1195.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 15, 2026CVE publishedPublication date reported by the CVE source.
  2. May 15, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 0.5.4, < 0.13.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Microsoft · APMversion=>= 0.5.4, < 0.13.0

Published CVSS scores

7.4GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor
CWE-59Improper Link Resolution Before File Access ('Link Following')
T1195.001Compromise Software Dependencies and Development Tools

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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