# CVE-2026-48092: 7-Zip heap memory disclosure in SquashFS ReadBlock

Source: https://junglewise.ai/threats/cve-2026-48092-7-zip-heap-memory-disclosure-in-squashfs-readblock  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-05. Updated: 2026-06-05  
License: CC BY 4.0 with a link back

CVE-2026-48092 · Severity: medium · CVSS 4.3 · Published 2026-06-05

7-Zip is a widely used file compression and archiving utility. A vulnerability in its 32-bit versions allows a specially crafted SquashFS archive to trick the software into reading and disclosing parts of the computer's memory during the extraction process. This could allow an attacker to steal sensitive information that happens to be stored in the system's memory at that time.

## Quick answers

**Is CVE-2026-48092 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-48092 being exploited in the wild.

**How severe is CVE-2026-48092?** Medium severity, with a CVSS score of 4.3, published 5 June 2026.

**Which products and versions are affected?** Igor Pavlov 7-Zip 9.34 through 26.00 (32-bit builds).

**Is there a fix for CVE-2026-48092?** 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-2026-48092 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-48092?** Check whether anything you run is named in the advisory. 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

An integer overflow vulnerability exists in the SquashFS ReadBlock function of 7-Zip 32-bit builds. The root cause is a lack of validation for the 'node.Offset' value read from the SquashFS inode. When calculating 'offsetInBlock + blockSize', a 32-bit unsigned integer wrap-around can occur, allowing the attacker-controlled offset to bypass fragment bounds checks. This results in a memcpy operation that reads heap memory preceding the cache buffer and writes it into the extracted output file. The issue is latent on 64-bit builds because the addition is promoted to 64 bits, preventing the overflow. The vulnerability was patched in version 26.01.

## Affected products

- Igor Pavlov 7-Zip 9.34 through 26.00 (32-bit builds)

## Timeline

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