A heap out‑of‑bounds read flaw exists in libarchive’s RAR extraction logic. The problem originates from inadequate validation of the LZSS sliding window size when the parser transitions between compression methods, enabling an attacker to read sensitive data from uninitialized heap memory. The flaw can be triggered by submitting a specially crafted RAR file and does not require authentication or user interaction, exposing the content of the vulnerable host to an attacker. The CWE associated with this weakness is Improper Memory Management – Out‑of‑Bound Read (CWE‑125).

Red Hat Enterprise Linux 10,6,7,8,9, Red Hat Hardened Images, and Red Hat OpenShift Container Platform 4 are affected through the libarchive library shipped with these distributions. Users of these platforms running applications that employ libarchive for RAR archive extraction should be aware of the vulnerability.

The CVSS score of 7.5 indicates a high impact vulnerability, yet the EPSS score of less than 1% suggests a low current exploitation probability. This issue is not listed in the CISA KEV catalog. While the advisory states no workaround meets Red Hat’s acceptance criteria, the attack path is inferred to involve the receipt of a malicious RAR file—either via local file upload or processed by a service component—leading to information disclosure. Absence of an official patch at this time elevates the need for monitoring and readiness to apply mitigations when available.