Arbitrary file read via unconfined reference resolution
Published Jul 16, 2026 · Updated Jul 16, 2026
Path traversal in Microsoft Prompty runtimes allows remote attackers to read local files through crafted .prompty files. Loaders expand untrusted ${file:...} frontmatter references and read the resolved target without first enforcing containment within the prompt directory or an allowed root. Exploitation requires an attacker-controlled prompt or prompt path; disclosure is limited to files readable by the host process and, in C# 2.0.0-beta.2 through 2.0.0-beta.3, can use an intermediate symlink or junction.
Summary
What happened
Path traversal in Microsoft Prompty runtimes allows remote attackers to read local files through crafted .prompty files. Loaders expand untrusted ${file:...} frontmatter references and read the resolved target without first enforcing containment within the prompt directory or an allowed root. Exploitation requires an attacker-controlled prompt or prompt path; disclosure is limited to files readable by the host process and, in C# 2.0.0-beta.2 through 2.0.0-beta.3, can use an intermediate symlink or junction.
The record
- CVE
- CVE-2026-53598
- Published
- Jul 16, 2026
- Updated
- Jul 16, 2026
- Vendor
- Microsoft
- Product
- Prompty
- Classifications
- CWE-200, CWE-22, T1005
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 16, 2026CVE publishedPublication date reported by the CVE source.
- Jul 16, 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.
- Affected versionversion=< 2.0.0-beta.2
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo