CVE-2026-4424 identifies a heap out-of-bounds read vulnerability in the libarchive library component of Red Hat Enterprise Linux 10, specifically within the RAR archive processing logic. The vulnerability stems from improper validation of the LZSS sliding window size after transitions between compression methods, which leads to reading beyond the allocated heap buffer. This flaw can be triggered remotely by an attacker providing a maliciously crafted RAR archive file. The vulnerability allows disclosure of sensitive heap memory information, potentially leaking confidential data such as cryptographic keys, passwords, or other sensitive process memory contents. Exploitation does not require any authentication or user interaction, making it easier to weaponize in automated attacks. However, the flaw does not permit code execution or modification of data, limiting its impact to confidentiality breaches. The CVSS 3.1 base score is 7.5 (high), reflecting the ease of remote exploitation and the high confidentiality impact. No patches or known exploits are currently reported, but given the severity, timely remediation is critical. The vulnerability affects all deployments of Red Hat Enterprise Linux 10 using the vulnerable libarchive version for RAR processing. Organizations relying on this platform for critical workloads are at risk of sensitive data leakage if exposed to untrusted RAR archives.

The primary impact of CVE-2026-4424 is the unauthorized disclosure of sensitive heap memory contents on systems running Red Hat Enterprise Linux 10. This can lead to leakage of confidential information such as encryption keys, credentials, or other sensitive data residing in memory, which attackers can leverage for further compromise or lateral movement. Since the vulnerability can be exploited remotely without authentication or user interaction, it poses a significant risk to exposed services or systems that process untrusted RAR archives. Although it does not allow direct code execution or data manipulation, the confidentiality breach can undermine system security and trust. Organizations handling sensitive data or operating in regulated industries face compliance and reputational risks. The scope includes all systems running the affected libarchive version on Red Hat Enterprise Linux 10, which is widely used in enterprise environments, cloud infrastructure, and government systems. The absence of known exploits currently reduces immediate risk, but the vulnerability’s characteristics make it a likely target for future attacks.

To mitigate CVE-2026-4424, organizations should: 1) Monitor Red Hat security advisories closely and apply official patches or updates for libarchive and Red Hat Enterprise Linux 10 as soon as they become available. 2) Implement strict input validation and filtering to block or sandbox untrusted RAR archives, especially in network-facing services or automated processing pipelines. 3) Employ network segmentation and access controls to limit exposure of systems that handle archive files to untrusted sources. 4) Use intrusion detection and prevention systems (IDS/IPS) with signatures to detect anomalous RAR archive processing or exploitation attempts. 5) Conduct regular memory and process monitoring to detect abnormal heap reads or information leaks. 6) Educate users and administrators about the risks of opening untrusted archive files and enforce policies to minimize such exposure. 7) Consider disabling RAR archive support in libarchive if not required, reducing the attack surface. These measures, combined with timely patching, will reduce the likelihood and impact of exploitation.