Vulnerability · Published May 28, 2026 · Assigned by CERT-PL
CVE-2026-42250Off-by-One Leading to Out-of-Bounds Write in bzip2
Medium 4.8
In plain English
A medium-severity out-of-bounds write in bzip2 from bzip2. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 2% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | bzip2 | no fix listed | DEBIAN-CVE-2026-42250 |
| Debian:13 | bzip2 | no fix listed | DEBIAN-CVE-2026-42250 |
| Debian:14 | bzip2 | no fix listed | DEBIAN-CVE-2026-42250 |
| Ubuntu:22.04:LTS | bzip2 | 1.0.8-5ubuntu0.1 | USN-8685-1 |
| Ubuntu:22.04:LTS | bzip2 | 1.0.8-5ubuntu0.1 | UBUNTU-CVE-2026-42250 |
| Ubuntu:24.04:LTS | bzip2 | 1.0.8-5.1ubuntu0.1 | USN-8685-1 |
| Ubuntu:24.04:LTS | bzip2 | 1.0.8-5.1ubuntu0.1 | UBUNTU-CVE-2026-42250 |
| Ubuntu:25.10 | bzip2 | no fix listed | UBUNTU-CVE-2026-42250 |
| Ubuntu:26.04:LTS | bzip2 | 1.0.8-6ubuntu0.1 | UBUNTU-CVE-2026-42250 |
| Ubuntu:26.04:LTS | bzip2 | 1.0.8-6ubuntu0.1 | USN-8685-1 |
| Ubuntu:26.10 | bzip2 | no fix listed | UBUNTU-CVE-2026-42250 |
Affected products (as reported)
Weakness: CWE-787 · Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N