CVE-2026-54063: excelize DoS — Exploit & Fix

Description

Excelize is a Go language library for reading and writing Microsoft Excel spreadsheets. Prior to 2.11.0, the checkSheet() function in github.com/xuri/excelize/v2 uses an attacker-controlled <row r="N"> XML attribute value directly as the length argument to make([]xlsxRow, row) without validating it against the Excel row limit (TotalRows = 1,048,576). A specially crafted XLSX file can trigger two denial-of-service variants: (A) an out-of-memory process kill when r=2147483647 forces a ~16 GB allocation attempt, and (B) a runtime panic via out-of-bounds slice indexing when r=-1. Any service that opens attacker-supplied XLSX files and calls GetCellValue is affected. No authentication is required. This issue is fixed in version 2.11.0.

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CVSS v3.1 Score

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploit Prediction

0.0061

Probability of exploitation

0.45%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-770 CWE-770

Affected Products

Vendor	Product	Versions
excelize	excelize	< 2.11.0

References

Advisories & Patches

https://github.com/qax-os/excelize/security/advisories/GHSA-h69g-9hx6-f3v4 https://github.com/qax-os/excelize/security/advisories/GHSA-h69g-9hx6-f3v4

Exploits

https://github.com/qax-os/excelize/security/advisories/GHSA-h69g-9hx6-f3v4 https://github.com/qax-os/excelize/security/advisories/GHSA-h69g-9hx6-f3v4

Other References

https://github.com/qax-os/excelize/releases/tag/v2.11.0

Frequently Asked Questions

What is CVE-2026-54063? +

Excelize is a Go language library for reading and writing Microsoft Excel spreadsheets. Prior to 2.11.0, the checkSheet() function in github.com/xuri/excelize/v2 uses an attacker-controlled <row r="N"> XML attribute value directly as the length argument to make([]xlsxRow, row) without validating it against the Excel row limit (TotalRows = 1,048,576). A specially crafted XLSX file can trigger two denial-of-service variants: (A) an out-of-memory process kill when r=2147483647 forces a ~16 GB allocation attempt, and (B) a runtime panic via out-of-bounds slice indexing when r=-1. Any service that opens attacker-supplied XLSX files and calls GetCellValue is affected. No authentication is required. This issue is fixed in version 2.11.0. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2026-54063? +

CVE-2026-54063 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0061, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-54063? +

CVE-2026-54063 affects products from excelize, specifically: excelize. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-54063? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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