CVE-2026-4424: Libarchive: libarchive: information disclosure via heap out-of-bounds read in rar archive processing
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.
Other sources
A Heap Out-of-Bounds Read vulnerability exists in the RAR archive processing logic of the libarchive library. The issue arises from improper validation of the LZSS sliding window size after transitions between compression methods (PPMd and LZSS). Due to a mismatch between the allocated buffer size and the expected dictionary size, the copyfromlzsswindow() function performs out-of-bounds memory reads. This allows a specially crafted RAR archive to leak heap memory through the archivereaddata() API before integrity checks (CRC) are enforced. The vulnerability can be exploited remotely without authentication or user interaction in systems that automatically process archives, leading to disclosure of sensitive information.
— Red Hat
Libarchive: libarchive: information disclosure via heap out-of-bounds read in rar archive processing
— Microsoft
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-4424?
CVE-2026-4424 is classified as a medium severity vulnerability due to its potential to lead to information disclosure.
How do I fix CVE-2026-4424?
To fix CVE-2026-4424, update to the latest version of libarchive that addresses this vulnerability.
What products are affected by CVE-2026-4424?
CVE-2026-4424 specifically affects the libarchive library used for processing RAR archives.
What type of vulnerability is CVE-2026-4424?
CVE-2026-4424 is an information disclosure vulnerability caused by a heap out-of-bounds read.
What can an attacker achieve with CVE-2026-4424?
An attacker exploiting CVE-2026-4424 could potentially read sensitive information from the heap memory.