CVE-2026-48112: 7-Zip heap out-of-bounds read in Ar and SquashFS handlers

CVE-2026-48112 · Severity: medium · CVSS 6.5 · Published 2026-06-05

7-Zip is a widely used file archiving utility for compressing and decompressing data. A vulnerability in how it handles certain archive formats could allow an attacker to read sensitive information from the computer's memory. This occurs when a user is tricked into opening a specially crafted archive file, potentially exposing private data to the attacker.

Technologies: 7-Zip. Vendors: 7-Zip.

Quick answers

Is CVE-2026-48112 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-48112 being exploited in the wild.
How severe is CVE-2026-48112?
Medium severity, with a CVSS score of 6.5, published 5 June 2026.
Which products and versions are affected?
7-Zip 9.18 through 26.00.
Is there a fix for CVE-2026-48112?
A patch was published on 2026-04-27: Version 26.01 released with fixes Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-48112 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-48112?
Check whether you run 7-Zip at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A heap out-of-bounds read exists in 7-Zip's Unix 'ar' archive parser and SquashFS handler. In the 'ar' parser, the ParseLibSymbols function reads a 32-bit namesSize field via Get32 at a position that can equal the buffer size, leading to a 4-byte out-of-bounds read of uninitialized heap data. Additionally, in 32-bit builds, the SquashFS handler's ReadBlock function is vulnerable to an integer overflow when calculating fragment offsets. An attacker can provide a crafted node.Offset that causes a wrap-around, bypassing bounds checks and allowing memcpy to read up to 8MB of heap memory preceding the buffer into the extracted file. Both issues require a user to open a malicious archive. The vulnerabilities are patched in version 26.01.

Affected products

  • 7-Zip 7-Zip 9.18 through 26.00

Timeline

  • 2026-04-21: disclosed: Reported to vendor via SourceForge private issues
  • 2026-04-27: patched: Version 26.01 released with fixes
  • 2026-06-05: advisory: NVD publication date

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