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PatchSiren cyber security CVE debrief

CVE-2026-48092 mcmilk CVE debrief

CVE-2026-48092 is a heap memory disclosure vulnerability in 7-Zip, a file archiver with a high compression ratio. Versions 9.34 through 26.00 are affected on 32-bit builds due to an integer overflow in the SquashFS ReadBlock function. This allows an attacker-controlled node.Offset value to bypass the fragment bounds check, causing memcpy to read heap memory preceding the cache buffer into the extracted file. The vulnerability is exploitable only on 32-bit builds of 7-Zip where size_t is 32 bits. Version 26.01 patches the issue.

Vendor
mcmilk
Product
7-Zip
CVSS
MEDIUM 4.3
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-05
Original CVE updated
2026-06-08
Advisory published
2026-06-05
Advisory updated
2026-06-08

Who should care

Users of 7-Zip on 32-bit systems, particularly those handling untrusted archive files, should be aware of this vulnerability and take steps to mitigate it.

Technical summary

The vulnerability is caused by a 32-bit integer overflow in the SquashFS ReadBlock function, which allows an attacker to bypass the fragment bounds check. This can lead to the disclosure of heap memory. The issue is only exploitable on 32-bit builds of 7-Zip.

Defensive priority

MEDIUM

Recommended defensive actions

  • Update to version 26.01 or later
  • Use 64-bit builds of 7-Zip for added security

Evidence notes

The CVE-2026-48092 vulnerability was published on [cve-org] and details can be found on [nvd]. Additional information and mitigation steps are available at [ref-4].

Official resources

CVE-2026-48092 was published on 2026-06-05T15:16:53.380Z and modified on 2026-06-08T18:16:33.553Z.