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CVE-2026-48112 mcmilk CVE debrief

CVE-2026-48112 is a medium-severity vulnerability in 7-Zip, a file archiver with a high compression ratio. Versions 9.18 through 26.00 are affected by a heap out-of-bounds read in the 7-Zip Ar handler BSD SYMDEF parser. The vulnerability occurs when parsing a BSD-style __.SYMDEF symbol table, where the ParseLibSymbols function reads a 32-bit namesSize field via Get32 at a position that can equal the buffer size, reading 4 bytes past the end of the heap allocation. This reads uninitialized heap data under the default allocator. The issue was patched in version 26.01.

Vendor
mcmilk
Product
7-Zip
CVSS
MEDIUM 6.5
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 versions 9.18 through 26.00 should update to version 26.01 or later to mitigate this vulnerability.

Technical summary

A 4-byte heap out-of-bounds read exists in the Unix ar archive parser in 7-Zip. When parsing a BSD-style __.SYMDEF symbol table, the ParseLibSymbols function reads a 32-bit namesSize field via Get32 at a position that can equal the buffer size, reading 4 bytes past the end of the heap allocation.

Defensive priority

Medium

Recommended defensive actions

  • Update 7-Zip to version 26.01 or later.

Evidence notes

CVE-2026-48112 was published on [cvePublishedAt] and modified on [cveModifiedAt]. The vulnerability has a CVSS score of 6.5 and is classified as CWE-125 and CWE-190.

Official resources

CVE-2026-48112 was published on 2026-06-05T17:16:49.353Z and modified on 2026-06-08T18:00:40.557Z.