Out-of-bounds Read Affecting 7zip package, versions <26.01-r0


Severity

Recommended
0.0
high
0
10

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Threat Intelligence

EPSS
0.23% (13th percentile)

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  • Snyk IDSNYK-ALPINE324-7ZIP-17376618
  • published19 Jun 2026
  • disclosed5 Jun 2026

Introduced: 5 Jun 2026

CVE-2026-48111  (opens in a new tab)
CWE-125  (opens in a new tab)

How to fix?

Upgrade Alpine:3.24 7zip to version 26.01-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream 7zip package and not the 7zip package as distributed by Alpine. See How to fix? for Alpine:3.24 relevant fixed versions and status.

7-Zip is a file archiver with a high compression ratio. Versions 9.21 through 26.00 contain an off-by-one out-of-bounds read vulnerability in the ParseDepedencyExpression function of the UEFI firmware image parser(CPP/7zip/Archive/UefiHandler.cpp). The function validates an attacker-controlled opcode byte using > instead of >= against the element count of the 10-entry kExpressionCommands static array, allowing an opcode value of 10 to read one pointer slot (8 bytes on x64) past the end of the array in .rodata. The out-of-bounds value is then dereferenced as a const char * and passed through strlen and memcpy into the archive's Characts property, which may cause either a denial of service (access violation when the adjacent bytes do not form a valid readable pointer) or a minor information disclosure of an adjacent .rdata string literal into archive metadata. The vulnerability is reached automatically during IInArchive::Open() via the call path OpenFv/OpenCapsule → ParseVolume → ParseSections when processing a SECTION_DXE_DEPEX (0x13) or SECTION_PEI_DEPEX (0x1B) section whose first body byte is 0x0A, and the UEFI handler is enabled by default in stock 7z.dll with signature-based detection for both UEFIc and UEFIf formats. The outcome (crash vs. silent leak) is deterministic per build but linker-layout dependent, with no write primitive and no disclosure of heap data, secrets, or ASLR base addresses. Version 26.01 fixes the issue.

CVSS Base Scores

version 3.1