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

Source: https://junglewise.ai/threats/cve-2026-48112-7-zip-heap-out-of-bounds-read-in-ar-and-squashfs-handlers  
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-2026-48112 · 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](https://junglewise.ai/threats/technologies/7-zip). Vendors: [7-Zip](https://junglewise.ai/threats/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

## Related threats

- [7-Zip heap overflow in XZ decompression](https://junglewise.ai/threats/cve-2026-14266-7-zip-heap-overflow-in-xz-decompression)
- [7-Zip Mark-of-the-Web bypass in RAR5 extraction](https://junglewise.ai/threats/cve-2026-58052-7-zip-mark-of-the-web-bypass-in-rar5-extraction)
- [7-Zip out-of-bounds read in UEFI firmware image parser](https://junglewise.ai/threats/cve-2026-48111-7-zip-out-of-bounds-read-in-uefi-firmware-image-parser)
- [7-Zip heap out-of-bounds read in WIM archive handler](https://junglewise.ai/threats/cve-2026-48103-7-zip-heap-out-of-bounds-read-in-wim-archive-handler)
- [7-Zip heap out-of-bounds read in UDF disc image handler](https://junglewise.ai/threats/cve-2026-48102-7-zip-heap-out-of-bounds-read-in-udf-disc-image-handler)