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.
Fix
Patch, vendor advisory and mitigation references on NVD 4
- https://github.com/qax-os/excelize/commit/db93f8d89de71589069a54d1b998af02e3c5f7cd Patch
- https://github.com/qax-os/excelize/pull/2369 Issue Tracking, Patch
- https://github.com/qax-os/excelize/security/advisories/GHSA-fw94-4wwp-w8pw Exploit, Vendor Advisory
- https://github.com/qax-os/excelize/security/advisories/GHSA-fw94-4wwp-w8pw Exploit, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 6.5 · excelizeNVD modified 2026-10-13 14:17
Affected (CPE criteria) 1
cpe:2.3:a:excelize:excelize:*:*:*:*:*:go:*:*
References 4
- https://github.com/qax-os/excelize/commit/db93f8d89de71589069a54d1b998af02e3c5f7cd Patch
- https://github.com/qax-os/excelize/pull/2369 Issue Tracking, Patch
- https://github.com/qax-os/excelize/security/advisories/GHSA-fw94-4wwp-w8pw Exploit, Vendor Advisory
- https://github.com/qax-os/excelize/security/advisories/GHSA-fw94-4wwp-w8pw Exploit, Vendor Advisory