NULL pointer dereference in Libarchive
CVE-2026-5745
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).
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.002 (5.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 6th percentile — 5.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000
Affected products
Weakness classification (CWE)
References
- access.redhat.com/errata/RHSA-2026:8944 (vendor-advisory)
- access.redhat.com/security/cve/CVE-2026-5745 (Third Party Advisory, vdb-entry)
- bugzilla.redhat.com/show_bug.cgi (issue-tracking, Third Party Advisory, Issue Tracking)
Frequently asked questions
- What is CVE-2026-5745?
- CVE-2026-5745 is a medium-severity vulnerability in Libarchive, classified under NULL Pointer Dereference. CVSS score: 5.5/10. Published 2026-04-07.
- How severe is CVE-2026-5745?
- Medium severity. CVSS v3 base score is 5.5 out of 10.