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).

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - 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). (CVE-2026-5745)

The Rocky Linux 9.6 host has packages installed that are affected by a vulnerability as referenced in the TuxCare ALMALINUX9.6:CLSA-2026:1776429223 advisory.

  - 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). (CVE-2026-5745)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The AlmaLinux 9.6 host has packages installed that are affected by a vulnerability as referenced in the TuxCare ALMALINUX9.6:CLSA-2026:1776429223 advisory.

  - 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). (CVE-2026-5745)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The AlmaLinux 9.2 host has packages installed that are affected by a vulnerability as referenced in the TuxCare ALMALINUX9.2:CLSA-2026:1776430169 advisory.

  - 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). (CVE-2026-5745)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

An update of the libarchive package has been released.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - 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). (CVE-2026-5745)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
461529	Echo: libarchive: security update to 3.7.4-4+e8	Tenable Cloud Security	Echo Local Security Checks	Local	medium
461529	Echo: libarchive: security update to 3.7.4-4+e8	Tenable Self-Hosted Container Security	Echo Local Security Checks	Local	medium
359695	Rocky Linux 9.6 [TuxCare] Security Update: bsdcat / bsdcpio / bsdtar / libarchive / libarchive-devel (ALMALINUX9.6:CLSA-2026:1776429223)	Nessus	Rocky Linux Local Security Checks	Local	medium
359572	AlmaLinux 9.6 [TuxCare] Security Update: bsdcat / bsdcpio / bsdtar / libarchive / libarchive-devel (ALMALINUX9.6:CLSA-2026:1776429223)	Nessus	Alma Linux Local Security Checks	Local	medium
352543	AlmaLinux 9.2 [TuxCare] Security Update: bsdcat / bsdcpio / bsdtar / libarchive / libarchive-devel (ALMALINUX9.2:CLSA-2026:1776430169)	Nessus	Alma Linux Local Security Checks	Local	medium
334032	Photon OS 5.0: Libarchive PHSA-2026-5.0-91-0825	Nessus	PhotonOS Local Security Checks	Local	critical
307888	Photon OS 5.0: Libarchive PHSA-2026-5.0-0825	Nessus	PhotonOS Local Security Checks	Local	critical
305212	Linux Distros Unpatched Vulnerability : CVE-2026-5745	Nessus	Misc.	Local	medium

Detections

Analytics

CVE-2026-5745

medium

Tenable Plugins

medium

medium

medium

medium

medium

critical

critical

medium