CVE-2026-42250

Utility crash via late block-limit check

Published May 28, 2026 · Updated May 28, 2026

Out-of-bounds write in bzip2recover in bzip2 1.0.8 and earlier allows local users to crash the utility via a crafted file. The block-scanning loop checks its limit one iteration late, then can access past the global bStart, bEnd, rbStart, and rbEnd arrays. A local user must cause bzip2recover to process the file; the demonstrated consequence is memory corruption and a utility crash, not code execution.

CVSS severity4.8
Medium
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Out-of-bounds write in bzip2recover in bzip2 1.0.8 and earlier allows local users to crash the utility via a crafted file. The block-scanning loop checks its limit one iteration late, then can access past the global bStart, bEnd, rbStart, and rbEnd arrays. A local user must cause bzip2recover to process the file; the demonstrated consequence is memory corruption and a utility crash, not code execution.

The record

CVE
CVE-2026-42250
Published
May 28, 2026
Updated
May 28, 2026
Vendor
bzip2
Product
bzip2
Classifications
CWE-787
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 28, 2026CVE publishedPublication date reported by the CVE source.
  2. May 28, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=1.0.8

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

bzip2 · bzip2version=0 <=1.0.8

Published CVSS scores

4.8CERT.PLCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
3.3SUSECVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
4.8SUSECVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo