# CVE-2026-42250: Off-by-One Leading to Out-of-Bounds Write in bzip2

CVE-2026-42250 is fixed in 2 products on 1 platform, first by bzip2 1.0.6-8.1ubuntu0.2+esm1, released May 28, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-42250
- Priority: Routine
- CVSS: n/a (Low)
- EPSS: 0.0013
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: May 28, 2026
- Weakness: Out-of-bounds Write
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42250

## Description

bzip2 contains an off‑by‑one error in the bzip2recover utility. When processing a specially crafted file, the application performs an out‑of‑bounds write to a global buffer, resulting in memory corruption and a crash (denial of service). This issue was fixed in bzip2 patch 35d122a3df8b0cc4082a4d89fdc6ee99f375fe67

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | bzip2 Ubuntu 18.04.6 LTS (bionic) | 1.0.6-8.1ubuntu0.2+esm1 | [bzip2 1.0.6-8.1ubuntu0.2+esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-bzip2-1.0.6-8.1ubuntu0.2-esm1.md) | May 28, 2026 |
| Linux | bzip2 Ubuntu 20.04 LTS (focal) | 1.0.8-2ubuntu0.1~esm1 | [bzip2 1.0.8-2ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-bzip2-1.0.8-2ubuntu0.1-esm1.md) | May 28, 2026 |
| Linux | bzip2 Ubuntu 22.04.1 LTS (jammy) | 1.0.8-5ubuntu0.1 | [bzip2 1.0.8-5ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-bzip2-1.0.8-5ubuntu0.1.md) | May 28, 2026 |
| Linux | bzip2 Ubuntu 24.04.5 LTS (noble) | 1.0.8-5.1ubuntu0.1 | [bzip2 1.0.8-5.1ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-noble-bzip2-1.0.8-5.1ubuntu0.1.md) | May 28, 2026 |
| Linux | bzip2 Ubuntu 26.04.1 LTS (resolute) | 1.0.8-6ubuntu0.1 | [bzip2 1.0.8-6ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-bzip2-1.0.8-6ubuntu0.1.md) | May 28, 2026 |
| Linux | bzip2 opensuse-leap 16.0 | 1.0.8-160000.3.1 | [OPENSUSE-SU-2026:21762-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21762-1.md) | Sep 4, 2026 |
| Linux | bzip2 sles 15.7 | 1.0.8-150400.3.4.1 | [SUSE-SU-2026:4055-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4055-1.md) | Sep 7, 2026 |
| Linux | bzip2 sles 16.0 | 1.0.8-160000.3.1 | [SUSE-SU-2026:23627-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23627-1.md) | Sep 4, 2026 |
| Linux | libbz2-1.0 Ubuntu 18.04.6 LTS (bionic) | 1.0.6-8.1ubuntu0.2+esm1 | [libbz2-1.0 1.0.6-8.1ubuntu0.2+esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libbz2-1.0-1.0.6-8.1ubuntu0.2-esm1.md) | May 28, 2026 |
| Linux | libbz2-1.0 Ubuntu 20.04 LTS (focal) | 1.0.8-2ubuntu0.1~esm1 | [libbz2-1.0 1.0.8-2ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libbz2-1.0-1.0.8-2ubuntu0.1-esm1.md) | May 28, 2026 |
| Linux | libbz2-1.0 Ubuntu 22.04.1 LTS (jammy) | 1.0.8-5ubuntu0.1 | [libbz2-1.0 1.0.8-5ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libbz2-1.0-1.0.8-5ubuntu0.1.md) | May 28, 2026 |
| Linux | libbz2-1.0 Ubuntu 24.04.5 LTS (noble) | 1.0.8-5.1ubuntu0.1 | [libbz2-1.0 1.0.8-5.1ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-noble-libbz2-1.0-1.0.8-5.1ubuntu0.1.md) | May 28, 2026 |
| Linux | libbz2-1.0 Ubuntu 26.04.1 LTS (resolute) | 1.0.8-6ubuntu0.1 | [libbz2-1.0 1.0.8-6ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-libbz2-1.0-1.0.8-6ubuntu0.1.md) | May 28, 2026 |

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Data as of 2026-11-08T19:12:23Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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