# CVE-2021-40399: Use after free in WPS Office

> A use-after-free vulnerability in WPS Spreadsheets allows remote code execution via a specially crafted XLS file.

- **Severity:** High 8.8 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 12 May 2022
- **Updated:** 15 Apr 2025
- **Also known as:** GHSA-gggr-phrh-226m

## What is CVE-2021-40399?

CVE-2021-40399 is a high-severity use after free vulnerability in WPS Office, published on 12 May 2022. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

An exploitable use-after-free vulnerability exists in WPS Spreadsheets ( ET ) as part of WPS Office, version 11.2.0.10351. A specially-crafted XLS file can cause a use-after-free condition, resulting in remote code execution. An attacker needs to provide a malformed file to the victim to trigger the vulnerability.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2021-40399?

It affects 1 product.


Products: Wps Wps Office.

## How do I fix CVE-2021-40399?

No fix has been published for CVE-2021-40399 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-40399 being exploited?

There is no known exploitation of CVE-2021-40399 in the wild and no public exploit code.

## Other vulnerabilities in WPS Office

- [CVE-2022-24934](https://insights.sbomify.com/CVE-2022-24934/): Privilege escalation in n/a (critical 9.8)
- [CVE-2018-6390](https://insights.sbomify.com/CVE-2018-6390/): Denial of service in n/a (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-40399 and fix it if it is affected.

What it is: CVE-2021-40399 is a high-severity use after free vulnerability in WPS Office, published on 12 May 2022. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-40399 in the wild and no public exploit code.

Affected product: WPS Office. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-40399/ (Markdown: https://insights.sbomify.com/CVE-2021-40399/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-40399
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-40399
- OSV: https://osv.dev/vulnerability/CVE-2021-40399

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-40399/
Summaries are generated and may contain mistakes; the official description above is the record.