CVE-2026-53598: Prompty: Arbitrary file read via file reference expansion

July 17, 2026 (updated August 3, 2026)

Prompty loaders expanded ${file:...} references in .prompty frontmatter without enforcing that the resolved path stayed within an authorized directory. An attacker-controlled prompt file could use path traversal or an absolute path to cause the host application to read files accessible to the process.

References

github.com/advisories/GHSA-wxhm-2mq7-7697
github.com/microsoft/prompty/commit/88ac9948d7d37995edbb2f6d36913436626c39e1
github.com/microsoft/prompty/security/advisories/GHSA-wxhm-2mq7-7697
nvd.nist.gov/vuln/detail/CVE-2026-53598

Code Behaviors & Features

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