CVE-2026-107224

Excelize: A Zip64 uncompressed-size of 2^63 panics OpenFile/OpenReader

Published Oct 7, 2026 CVSS 3.1 · 6.5 Medium EPSS < 1% KEV · Not listed
Description
Excelize is a Go language library for reading and writing Microsoft Excel spreadsheets. From 2.1.0 to 2.11.0, a Zip64 uncompressed size with the high bit set is converted from uint64 to a negative int64 before signed size-limit checks and allocation. ReadZipReader obtains UncompressedSize64 through FileInfo.Size and passes the wrapped negative value to readFile. When a crafted Zip64 entry declares an uncompressed size from 2^63 through 2^64-1 and the workbook is opened, the negative size bypasses unzip limits and reaches make as a negative capacity, allowing an attacker to panic during workbook opening. No fixed version is available as of this review.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-fw94-4wwp-w8pw Excelize: A Zip64 uncompressed-size of 2^63 panics OpenFile/OpenReader
History
Type Values Removed Values Added
First Time appeared Excelize
Excelize excelize
CPEs cpe:2.3:a:excelize:excelize:*:*:*:*:*:go:*:*
Vendors & Products Excelize
Excelize excelize
Type Values Removed Values Added
First Time appeared Qax-os
Qax-os excelize
Vendors & Products Qax-os
Qax-os excelize
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Excelize is a Go language library for reading and writing Microsoft Excel spreadsheets. From 2.1.0 to 2.11.0, a Zip64 uncompressed size with the high bit set is converted from uint64 to a negative int64 before signed size-limit checks and allocation. ReadZipReader obtains UncompressedSize64 through FileInfo.Size and passes the wrapped negative value to readFile. When a crafted Zip64 entry declares an uncompressed size from 2^63 through 2^64-1 and the workbook is opened, the negative size bypasses unzip limits and reaches make as a negative capacity, allowing an attacker to panic during workbook opening. No fixed version is available as of this review.
Title Excelize: A Zip64 uncompressed-size of 2^63 panics OpenFile/OpenReader
Weaknesses CWE-190
CWE-681
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Oct 7, 2026, 7:30 PM
Reserved
Oct 7, 2026, 2:34 PM
Status
Analyzed
Published
Oct 7, 2026, 7:17 PM
Modified
Oct 13, 2026, 2:17 PM