CVE-2026-4424

High

Published: 19 March 2026

Published

19 March 2026

Modified

11 May 2026

KEV Added

—

Patch

—

CVSS Score 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS Score 0.0036 58.5th percentile

Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-4424 is a high-severity Out-of-bounds Read (CWE-125) vulnerability in Redhat Enterprise Linux. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 41.5% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 RA-5 (Vulnerability Monitoring and Scanning) and SI-2 (Flaw Remediation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190). What defenders deploy: see the NIST 800-53 controls recommended below.

Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

SI-2 Flaw Remediation good match

prevent

SI-2 mandates timely identification, reporting, and correction of software flaws like the heap out-of-bounds read in libarchive's RAR processing, directly preventing exploitation via crafted archives.

RA-5 Vulnerability Monitoring and Scanning good match

detect

RA-5 requires vulnerability scanning to identify systems running vulnerable versions of libarchive affected by CVE-2026-4424, enabling proactive patching.

SI-16 Memory Protection partial match

prevent

SI-16 implements memory protections such as ASLR and heap guards that mitigate heap out-of-bounds reads by randomizing memory layout and detecting corruption attempts.

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access

Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.

attack.mitre.org →

Why these techniques?

Remote unauthenticated exploitation of a public-facing application via crafted RAR input to libarchive directly enables information disclosure from heap memory.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

A flaw was found in libarchive. This heap out-of-bounds read vulnerability exists in the RAR archive processing logic due to improper validation of the LZSS sliding window size after transitions between compression methods. A remote attacker can exploit this by…

providing a specially crafted RAR archive, leading to the disclosure of sensitive heap memory information without requiring authentication or user interaction.

Deeper analysisAI

CVE-2026-4424 is a heap out-of-bounds read vulnerability in libarchive, specifically within the RAR archive processing logic. The flaw arises from improper validation of the LZSS sliding window size following transitions between compression methods. This issue, published on 2026-03-19, carries a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N) and is classified under CWE-125 (Out-of-bounds Read).

A remote attacker can exploit this vulnerability by providing a specially crafted RAR archive, without requiring authentication or user interaction. Successful exploitation leads to the disclosure of sensitive heap memory information, enabling potential information leakage from affected systems processing the malicious archive.

Red Hat has issued multiple errata addressing this vulnerability in their products, including RHSA-2026:10065, RHSA-2026:10097, RHSA-2026:11768, RHSA-2026:8492, and RHSA-2026:8510, which provide updated packages with mitigation through patches to libarchive.