CVE-2026-5745
Publication date 7 April 2026
Last updated 13 May 2026
Ubuntu priority
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).
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| libarchive | 26.04 LTS resolute |
Vulnerable
|
| 25.10 questing |
Vulnerable
|
|
| 24.04 LTS noble |
Vulnerable
|
|
| 22.04 LTS jammy |
Vulnerable
|
|
| 20.04 LTS focal |
Vulnerable
|
|
| 18.04 LTS bionic |
Vulnerable
|
|
| 16.04 LTS xenial |
Vulnerable
|
|
| 14.04 LTS trusty |
Vulnerable
|
Notes
mdeslaur
There is a commit to fix this issue, but the CVE will likely be rejected by libarchive developers.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score |
5.5 · Medium
|
| Attack vector | Local |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | Required |
| Scope | Unchanged |
| Confidentiality | None |
| Integrity impact | None |
| Availability impact | High |
| Vector | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H |