CVE-2026-5745
libarchive: A NULL pointer dereference vulnerability exists in the ACL parser of libarchive
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · April 7, 2026
Updated · September 1, 2026
Description
A flaw was found in libarchive. A NULL pointer dereference vulnerability exists in the ACL parsing logic, specifically within the archive_acl_from_text_nl() function. When processing a malformed ACL string (such as a bare "d" or "default" tag without subsequent fields), the function fails to perform adequate validation before advancing the pointer. An attacker can exploit this by providing a maliciously crafted archive, causing an application utilizing the libarchive API (such as bsdtar) to crash, resulting in a Denial of Service (DoS).
Statement
This Moderate impact vulnerability in libarchive's ACL parsing logic can lead to a Denial of Service. An attacker could provide a specially crafted archive, causing applications that utilize the libarchive API, such as bsdtar, to crash when processing the malformed ACL string. This issue affects systems where applications process untrusted archives.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
CVSS / CWE
CVSS 3.1 · 5.5CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
CWE-476 · NULL Pointer Dereference