# CVE-2026-54063: Excelize unbounded memory allocation in checkSheet function

Source: https://junglewise.ai/threats/cve-2026-54063-excelize-unbounded-memory-allocation-in-checksheet-function  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-10. Updated: 2026-07-10  
License: CC BY 4.0 with a link back

CVE-2026-54063 · Severity: high · CVSS 7.5 · Published 2026-07-10

A vulnerability in the Excelize library, used by Go applications to process Excel files, allows an attacker to crash the application or exhaust its memory. By providing a specially crafted spreadsheet file, an attacker can force the system to attempt a massive memory allocation or trigger a software error. This can lead to a complete service outage for any application that processes user-uploaded Excel documents.

Technologies: [github.com/xuri/excelize/v2 (Go)](https://junglewise.ai/threats/technologies/github-com-xuri-excelize-v2), [Xuri Excelize](https://junglewise.ai/threats/technologies/excelize). Vendors: [Go](https://junglewise.ai/threats/vendors/go), [Xuri](https://junglewise.ai/threats/vendors/xuri).

## Quick answers

**Is CVE-2026-54063 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-54063 being exploited in the wild.

**How severe is CVE-2026-54063?** High severity, with a CVSS score of 7.5, published 10 July 2026.

**Which products and versions are affected?** github.com/xuri/excelize/v2 (Go) < 2.11.0, SEMVER:introduced=0,fixed=2.11.0; Xuri Excelize < 2.11.0.

**Is there a fix for CVE-2026-54063?** Yes. github.com/xuri/excelize/v2 (Go): upgrade to 2.11.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-54063 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-54063?** Check whether you run github.com/xuri/excelize/v2 (Go) or Xuri Excelize at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/xuri/excelize/v2 (Go): upgrade to 2.11.0 or later

  ```sh
  go get github.com/xuri/excelize/v2@v2.11.0
  ```


## Technical details

The vulnerability exists in the `checkSheet()` function within `github.com/xuri/excelize/v2`. The parser reads the `<row r="N">` XML attribute and uses it directly as a length argument for `make([]xlsxRow, row)` without validating it against the `TotalRows` limit (1,048,576). An attacker can provide a large integer (e.g., 2147483647) to trigger an out-of-memory (OOM) fatal error or a negative value (e.g., -1) to trigger a runtime panic due to out-of-bounds slice indexing. The issue is reachable via public APIs like `GetCellValue` that internally invoke the worksheet reader. A fix is available in version 2.11.0.

## Affected products

- xuri excelize < 2.11.0

## Identifiers

- CVE-2026-54063
- GHSA-h69g-9hx6-f3v4
- GO-2026-5960

## Timeline

- 2026-06-03: disclosed
- 2026-07-10: advisory: GHSA-h69g-9hx6-f3v4 published
- 2026-07-10: patched: Fixed in version 2.11.0

## References

- [https://api.github.com/users/EQSTLab](https://api.github.com/users/EQSTLab)
- [https://github.com/EQSTLab](https://github.com/EQSTLab)
- [https://api.github.com/users/EQSTLab/gists%7B/gist_id%7D](https://api.github.com/users/EQSTLab/gists%7B/gist_id%7D)
- [https://api.github.com/users/EQSTLab/repos](https://api.github.com/users/EQSTLab/repos)
- [https://avatars.githubusercontent.com/u/148991397?v=4](https://avatars.githubusercontent.com/u/148991397?v=4)
- [https://api.github.com/users/EQSTLab/events%7B/privacy%7D](https://api.github.com/users/EQSTLab/events%7B/privacy%7D)

## Related threats

- [Excelize unchecked pivot-cache field index bounds in extractPivotTableFields](https://junglewise.ai/threats/cve-2026-107211-excelize-unchecked-pivot-cache-field-index-in)
- [Excelize unbounded row iteration denial of service](https://junglewise.ai/threats/cve-2026-107212-excelize-unbounded-row-number-in-rows-columns-makes-getrows-and)
- [Excelize nil-pointer dereference in GetSlicers](https://junglewise.ai/threats/cve-2026-107213-excelize-nil-pointer-dereference-in-getslicers-when-a-worksheet)
- [Excelize Decrypt panic on malformed OLE encrypted workbooks](https://junglewise.ai/threats/cve-2026-107214-excelize-decrypt-unrecoverable-panics-on-malformed-ole-cfb)
- [Excelize extractPart unbounded buffer allocation DoS](https://junglewise.ai/threats/cve-2026-107215-excelize-extractpart-allocates-attacker-controlled-unbounded-and)