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Jenkins Arbitrary File Read Vulnerability Leaks Secrets from C...

A critical arbitrary file read vulnerability in Jenkins allows attackers to extract credentials, API keys, and secrets from CI/CD pipelines.

By Danny Mercer, CISSP — Lead Security Analyst Mar 4, 2026

Executive Summary

CVE-2026-27198 allows unauthenticated file read from Jenkins controller. Attackers can extract encrypted credentials AND the master decryption key, compromising all stored secrets.

Technical Analysis

The CLI-over-HTTP functionality enables file system traversal. Attackers extracting AWS/Azure credentials then pivot to cloud environments. Active exploitation observed.

Remediation

Update to Jenkins 2.442 or LTS 2.426.4. Restrict network access to Jenkins controller. Disable CLI-over-HTTP if patching delayed. Audit and rotate all credentials Jenkins has access to.

References

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