CVE-2026-107224
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.
Does this matter?
Lower severity and a low EPSS score (0.31%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
- EPSS
- 0.31% probability · 23th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-190, CWE-681
- Affected
- excelize/excelize
- Source
- security-advisories@github.com
EPSS moved from 0.4% on 8 October 2026 to 0.3% on 26 October 2026.
References
- https://github.com/qax-os/excelize/commit/db93f8d89de71589069a54d1b998af02e3c5f7cdPatch
- https://github.com/qax-os/excelize/pull/2369Issue Tracking, Patch
- https://github.com/qax-os/excelize/security/advisories/GHSA-fw94-4wwp-w8pwExploit, Vendor Advisory
- https://github.com/qax-os/excelize/security/advisories/GHSA-fw94-4wwp-w8pwExploit, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.