mcmilk 7-Zip up to 26.0 Unix Ar Archive Parser ParseLibSymbols integer overflow

Summaryinfo

A vulnerability was found in mcmilk 7-Zip up to 26.0. It has been classified as problematic. The impacted element is the function ParseLibSymbols of the component Unix Ar Archive Parser. This manipulation causes integer overflow. This vulnerability is tracked as CVE-2026-48112. The attack is possible to be carried out remotely. No exploit exists. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability classified as problematic was found in mcmilk 7-Zip up to 26.0. Affected by this vulnerability is the function ParseLibSymbols of the component Unix Ar Archive Parser. The manipulation with an unknown input leads to a integer overflow vulnerability. The CWE definition for the vulnerability is CWE-190. The product performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control. As an impact it is known to affect confidentiality. The summary by CVE is:

7-Zip is a file archiver with a high compression ratio. Versions 9.18 through 26.00 contain a heap out-of-bounds read in 7-Zip Ar handler BSD SYMDEF parser. 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. This reads uninitialized heap data under the default allocator. Version 26.01 patches the issue.

It is possible to read the advisory at securitylab.github.com. This vulnerability is known as CVE-2026-48112 since 05/20/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 26.01 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-34857). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

• File Compression Software

Vendor

• mcmilk

Name

• 7-Zip

Version

• 26.0

CPE 2.3info

• 🔒

CPE 2.2info

• 🔒

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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