# CVE-2026-5745: Libarchive: a null pointer dereference vulnerability exists in the acl parser of libarchive

> A null pointer dereference in libarchive's ACL parser allows attackers to cause a denial of service via crafted archives.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 7 Apr 2026
- **Updated:** 1 Sep 2026
- **Also known as:** CLSA-2026-1776429223, CLSA-2026-1776430169, DEBIAN-CVE-2026-5745, ECHO-56a7-5917-6302, GHSA-fjqv-vj6q-4fcm, MINI-wr42-pmv9-vrfw, UBUNTU-CVE-2026-5745

## What is CVE-2026-5745?

CVE-2026-5745 is a medium-severity vulnerability in Libarchive Libarchive, published on 7 Apr 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official 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).

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-5745?

It affects 4 products.


Products: Libarchive Libarchive, Redhat Enterprise Linux, Redhat Hardened Images, Redhat Openshift Container Platform.

## How do I fix CVE-2026-5745?

Apply the vendor's patch.

## Is CVE-2026-5745 being exploited?

There is no known exploitation of CVE-2026-5745 in the wild and no public exploit code.

## Other vulnerabilities in Libarchive Libarchive

- [CVE-2024-37407](https://insights.sbomify.com/CVE-2024-37407/): Memory corruption in n/a (critical 9.1)
- [CVE-2016-1541](https://insights.sbomify.com/CVE-2016-1541/): Memory corruption in n/a (high 8.8)
- [CVE-2016-6250](https://insights.sbomify.com/CVE-2016-6250/): Integer overflow in n/a (high 8.6)
- [CVE-2025-5914](https://insights.sbomify.com/CVE-2025-5914/): Libarchive: double free at archive_read_format_rar_seek_data() in archive_read_support_format_rar.c (high 7.8)
- [CVE-2024-48957](https://insights.sbomify.com/CVE-2024-48957/): Memory corruption in n/a (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-5745 and fix it if it is affected.

What it is: CVE-2026-5745 is a medium-severity vulnerability in Libarchive Libarchive, published on 7 Apr 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-5745 in the wild and no public exploit code.

Affected product: Libarchive Libarchive. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-5745/ (Markdown: https://insights.sbomify.com/CVE-2026-5745/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-5745
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-5745
- OSV: https://osv.dev/vulnerability/CVE-2026-5745

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-5745/
Summaries are generated and may contain mistakes; the official description above is the record.