CVE-2026-107224 · GHSA-fw94-4wwp-w8pw

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

Risk score: 54/100
CVSS: 6.5 v3.1
Exploit chance (30 days): 0.3%
Published: 7 Oct 2026

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What to know

What it is: 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 p…
Affected: github.com/xuri/excelize/v2 (go) >= 2.1.0, < 2.11.1-0.20260805032953-db93f8d89de7
Fix: Upgrade github.com/xuri/excelize/v2 to 2.11.1-0.20260805032953-db93f8d89de7 or later.
Exploitation: Public proof of concept

Story map

Story map: the flaws, the fix, how it unfolded and what it connects to. Boxes link to the record or article.

At a glance

github.com/xuri/excelize/v2: Amber, patch this week. Excelize is a Go language library for reading and writing Microsoft Excel spreadsheets. From 2.1.0 to 2.11.0, flatCols expands file-loaded column ranges without validating Min and Max against the worksheet column limit. SetColWidth reaches flatCols, which expands xlsxCol.Min through xlsxCol.Max without enforcing MaxCo…

The flaws

CVE-2026-107224: Excelize: A Zip64 uncompressed-size of 2^63 panics OpenFile/OpenReader (CVSS 6.5 · EPSS 0%)
CVE-2026-107223: Excelize: Unbounded <col max> attribute is loaded with no MaxColumns check and expanded per-column by flatCols(), so any column mutator hangs or OOMs the process (CVSS 7.5 · EPSS 0%)
CVE-2026-107212: Excelize: Unbounded row number in Rows.Columns makes GetRows and the Rows iterator loop for days (CVSS 7.5 · EPSS 0%)
CVE-2026-107217: Excelize ColumnNameToNumber: int64 overflow yields an out-of-domain coordinate with nil error, causing negative slice index panic on r="0" rows (CVSS 7.5 · EPSS 0%)

The fix

Fix: Upgrade github.com/xuri/excelize/v2 to 2.11.1-0.20260807015645-a54c578af309 or later.

Who is exposed: github.com/xuri/excelize/v2 (go) >= 2.1.0, < 2.11.1-0.20260807015645-a54c578af309

Where it stands

Public proof of concept

Connects to

Same weakness: Integer overflow (CWE-190). 124 other warnings in 30 days
Same product: Earlier github.com/xuri/excelize/v2 warnings. 11 in the last 90 days

Why it is Yellow

CVSS 6.5 medium
Public exploit or proof of concept referenced
On your watchlist: Go

Affected packages

Package	Ecosystem	Vulnerable	Fixed in
github.com/xuri/excelize/v2	go	>= 2.1.0, < 2.11.1-0.20260805032953-db93f8d89de7	2.11.1-0.20260805032953-db93f8d89de7

References

Original 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.

Last activity 7 Oct 2026. Patch Forecast updates every hour.