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Public proof of conceptFix available

CVE-2026-107224

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

A public proof of concept exists; no exploitation attested.

  • Published2026-10-07
  • WeaknessCWE-190 · CWE-681

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC
  1. 2026-10-0719:17CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-107224?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-107224?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD · OSV
Excelize
BranchAffectedFixed in
2.x≥ 2.1.0, ≤ 2.11.0no fix published
xuri/excelize
BranchAffectedFixed in
2.x≥ 2.1.0, < 2.11.1-0.20260805032953-db93f8d89de72.11.1-0.20260805032953-db93f8d89de7

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

  • NVDCVE recordread 2026-10-23
  • CISA-ADPSSVC decisionpoc2026-10-07
  • OpenCVESSVC decisionpoc—
  • CNACVSS 3.16.5read 2026-10-23
  • CNAweakness (CWE)CWE-190, CWE-681read 2026-10-23
  • FIRST EPSSEPSS score0.3 %2026-10-22
  • OSVaffected packages—

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Published
2026-10-07
Last Modified
2026-10-13
NVD status
Analyzed

Frequently asked questions

What is CVE-2026-107224?

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.

Is CVE-2026-107224 actively exploited?

A proof-of-concept exploit exists for CVE-2026-107224, but active exploitation has not been confirmed at this time.

What is the CVSS score for CVE-2026-107224?

CVE-2026-107224 has a CVSS v3 base score of 6.5 (MEDIUM severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

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