# CVE-2026-4111: Libarchive: infinite loop denial of service in rar5 decompression via archive_read_data() in libarchive

> Attackers can cause persistent denial of service in applications using Libarchive by submitting crafted RAR5 archives that trigger an infinite loop during decompression.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 13 Mar 2026
- **Updated:** 14 Oct 2026
- **Also known as:** ALSA-2026:5063, ALSA-2026:5080, AZL-79886, BELL-CVE-2026-4111, CLSA-2026-1774375084, CLSA-2026-1774375835, DEBIAN-CVE-2026-4111, ECHO-bb19-1016-174f, GHSA-xrqh-48jh-pjv2, OESA-2026-1641, RHSA-2026:5063, RHSA-2026:5080, RHSA-2026:6647, RHSA-2026:7093, RHSA-2026:7105, RHSA-2026:7106, RLSA-2026:5063, RLSA-2026:5080, UBUNTU-CVE-2026-4111

## What is CVE-2026-4111?

CVE-2026-4111 is a high-severity denial of service vulnerability in Cert Manager support for Red Hat OpenShift release 1.18, published on 13 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A flaw was identified in the RAR5 archive decompression logic of the libarchive library, specifically within the archive_read_data() processing path. When a specially crafted RAR5 archive is processed, the decompression routine may enter a state where internal logic prevents forward progress. This condition results in an infinite loop that continuously consumes CPU resources. Because the archive passes checksum validation and appears structurally valid, affected applications cannot detect the issue before processing. This can allow attackers to cause persistent denial-of-service conditions in services that automatically process archives.

Weakness: CWE-835 (Loop with Unreachable Exit Condition)

## Which versions are affected by CVE-2026-4111?


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `bsdtar` | AlmaLinux:10 | All versions | 3.7.7-5.el10_1 |
| `libarchive` | AlmaLinux:10 | All versions | 3.7.7-5.el10_1 |
| `libarchive-devel` | AlmaLinux:10 | All versions | 3.7.7-5.el10_1 |
| `bsdtar` | AlmaLinux:9 | All versions | 3.5.3-7.el9_7 |
| `libarchive` | AlmaLinux:9 | All versions | 3.5.3-7.el9_7 |
| `libarchive-devel` | AlmaLinux:9 | All versions | 3.5.3-7.el9_7 |
| `bsdcat-debuginfo` | Red Hat:enterprise_linux:10.1 | All versions | 0:3.7.7-5.el10_1 |
| `bsdcpio-debuginfo` | Red Hat:enterprise_linux:10.1 | All versions | 0:3.7.7-5.el10_1 |
| `bsdtar` | Red Hat:enterprise_linux:10.1 | All versions | 0:3.7.7-5.el10_1 |
| `bsdtar-debuginfo` | Red Hat:enterprise_linux:10.1 | All versions | 0:3.7.7-5.el10_1 |
| `bsdunzip-debuginfo` | Red Hat:enterprise_linux:10.1 | All versions | 0:3.7.7-5.el10_1 |
| `libarchive` | Red Hat:enterprise_linux:10.1 | All versions | 0:3.7.7-5.el10_1 |
| `libarchive-debuginfo` | Red Hat:enterprise_linux:10.1 | All versions | 0:3.7.7-5.el10_1 |
| `libarchive-debugsource` | Red Hat:enterprise_linux:10.1 | All versions | 0:3.7.7-5.el10_1 |
| `libarchive-devel` | Red Hat:enterprise_linux:10.1 | All versions | 0:3.7.7-5.el10_1 |
| `bsdcat-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 0:3.5.3-7.el9_7 |
| `bsdcpio-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 0:3.5.3-7.el9_7 |
| `bsdtar` | Red Hat:enterprise_linux:9::appstream | All versions | 0:3.5.3-7.el9_7 |
| `bsdtar-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 0:3.5.3-7.el9_7 |
| `libarchive-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 0:3.5.3-7.el9_7 |
| `libarchive-debugsource` | Red Hat:enterprise_linux:9::appstream | All versions | 0:3.5.3-7.el9_7 |
| `libarchive-devel` | Red Hat:enterprise_linux:9::appstream | All versions | 0:3.5.3-7.el9_7 |
| `bsdcat-debuginfo` | Red Hat:enterprise_linux:9::baseos | All versions | 0:3.5.3-7.el9_7 |
| `bsdcpio-debuginfo` | Red Hat:enterprise_linux:9::baseos | All versions | 0:3.5.3-7.el9_7 |
| `bsdtar-debuginfo` | Red Hat:enterprise_linux:9::baseos | All versions | 0:3.5.3-7.el9_7 |
| `libarchive` | Red Hat:enterprise_linux:9::baseos | All versions | 0:3.5.3-7.el9_7 |
| `libarchive-debuginfo` | Red Hat:enterprise_linux:9::baseos | All versions | 0:3.5.3-7.el9_7 |
| `libarchive-debugsource` | Red Hat:enterprise_linux:9::baseos | All versions | 0:3.5.3-7.el9_7 |
| `bsdcat-debuginfo` | Red Hat:rhel_e4s:9.0::appstream | All versions | 0:3.5.3-2.el9_0.3 |
| `bsdcpio-debuginfo` | Red Hat:rhel_e4s:9.0::appstream | All versions | 0:3.5.3-2.el9_0.3 |
| `bsdtar` | Red Hat:rhel_e4s:9.0::appstream | All versions | 0:3.5.3-2.el9_0.3 |
| `bsdtar-debuginfo` | Red Hat:rhel_e4s:9.0::appstream | All versions | 0:3.5.3-2.el9_0.3 |
| `libarchive-debuginfo` | Red Hat:rhel_e4s:9.0::appstream | All versions | 0:3.5.3-2.el9_0.3 |
| `libarchive-debugsource` | Red Hat:rhel_e4s:9.0::appstream | All versions | 0:3.5.3-2.el9_0.3 |
| `bsdcat-debuginfo` | Red Hat:rhel_e4s:9.0::baseos | All versions | 0:3.5.3-2.el9_0.3 |
| `bsdcpio-debuginfo` | Red Hat:rhel_e4s:9.0::baseos | All versions | 0:3.5.3-2.el9_0.3 |
| `bsdtar-debuginfo` | Red Hat:rhel_e4s:9.0::baseos | All versions | 0:3.5.3-2.el9_0.3 |
| `libarchive` | Red Hat:rhel_e4s:9.0::baseos | All versions | 0:3.5.3-2.el9_0.3 |
| `libarchive-debuginfo` | Red Hat:rhel_e4s:9.0::baseos | All versions | 0:3.5.3-2.el9_0.3 |
| `libarchive-debugsource` | Red Hat:rhel_e4s:9.0::baseos | All versions | 0:3.5.3-2.el9_0.3 |

## How do I fix CVE-2026-4111?

Apply the vendor's patch.

## Is CVE-2026-4111 being exploited?

There is no known exploitation of CVE-2026-4111 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-4111 and fix it if it is affected.

What it is: CVE-2026-4111 is a high-severity denial of service vulnerability in Cert Manager support for Red Hat OpenShift release 1.18, published on 13 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-4111 in the wild and no public exploit code.

Affected product: Cert Manager support for Red Hat OpenShift release 1.18. 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-2026-4111/ (Markdown: https://insights.sbomify.com/CVE-2026-4111/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-4111
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-4111
- OSV: https://osv.dev/vulnerability/CVE-2026-4111

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-4111/
Summaries are generated and may contain mistakes; the official description above is the record.