# CVE-2025-3500: Integer Overflow in Avast Antiviurs 25.1.981.6 on Windows may result in privilege escalation

> An integer overflow in Avast Antivirus allows attackers to escalate privileges on Windows systems.

- **Severity:** Critical 9.0 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 1 Dec 2025
- **Updated:** 26 Feb 2026
- **Also known as:** GHSA-28rh-r6hp-jmq3

## What is CVE-2025-3500?

CVE-2025-3500 is a critical vulnerability in Avast Antivirus, published on 1 Dec 2025. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

Integer Overflow or Wraparound vulnerability in Avast Antivirus (25.1.981.6) on Windows allows Privilege Escalation.This issue affects Antivirus: from 25.1.981.6 before 25.3.

Weakness: CWE-190 (Integer Overflow or Wraparound)

## Which versions are affected by CVE-2025-3500?

It affects 1 product.


Products: Avast Antivirus.

## How do I fix CVE-2025-3500?

No fix has been published for CVE-2025-3500 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-3500 being exploited?

There is no known exploitation of CVE-2025-3500 in the wild and no public exploit code.

Public exploit code:

- Public exploit for CVE-2025-3500 (github_poc): https://github.com/chicken3962/CVE-2025-3500-Poc

## Other vulnerabilities in Avast Antivirus

- [CVE-2025-13032](https://insights.sbomify.com/CVE-2025-13032/): Race condition in (Free/Inernet Security/Ultimate) Antivirus (critical 9.9)
- [CVE-2020-10867](https://insights.sbomify.com/CVE-2020-10867/): Security feature bypass in n/a (critical 9.8)
- [CVE-2017-8307](https://insights.sbomify.com/CVE-2017-8307/): Missing authorization in n/a (critical 9.8)
- [CVE-2021-45335](https://insights.sbomify.com/CVE-2021-45335/): Missing authorization in n/a (high 8.8)
- [CVE-2021-45336](https://insights.sbomify.com/CVE-2021-45336/): Privilege escalation vulnerability in the Sandbox component of Avast Antivirus prior to 20.4 allows a local sandboxed code to gain elevated (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-3500 and fix it if it is affected.

What it is: CVE-2025-3500 is a critical vulnerability in Avast Antivirus, published on 1 Dec 2025. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2025-3500 in the wild and no public exploit code.

Affected product: Avast Antivirus. 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-2025-3500/ (Markdown: https://insights.sbomify.com/CVE-2025-3500/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-3500
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-3500
- OSV: https://osv.dev/vulnerability/CVE-2025-3500

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-3500/
Summaries are generated and may contain mistakes; the official description above is the record.