# CVE-2026-20639: Integer overflow in macOS

> An integer overflow in macOS allows attackers to cause heap corruption and potentially execute arbitrary code via a maliciously crafted string.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 25 Mar 2026
- **Updated:** 2 Apr 2026
- **Also known as:** GHSA-7gg2-3r7f-v522

## What is CVE-2026-20639?

CVE-2026-20639 is a high-severity vulnerability in Apple Macos, published on 25 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An integer overflow was addressed with improved input validation. This issue is fixed in macOS Sequoia 15.7.5, macOS Sonoma 14.8.5, macOS Tahoe 26.3. Processing a maliciously crafted string may lead to heap corruption.

Weakness: CWE-190 (Integer Overflow or Wraparound)

## Which versions are affected by CVE-2026-20639?

It affects 1 product.


Products: Apple Macos.

## How do I fix CVE-2026-20639?

No fix has been published for CVE-2026-20639 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-20639 being exploited?

There is no known exploitation of CVE-2026-20639 in the wild and no public exploit code.

## Other vulnerabilities in Apple Macos

- [CVE-2026-65400](https://insights.sbomify.com/CVE-2026-65400/): Apple macOS Improper Authentication (critical 9.8, exploited in the wild)
- [CVE-2024-44146](https://insights.sbomify.com/CVE-2024-44146/): Security feature bypass in macOS (critical 10.0)
- [CVE-2024-44148](https://insights.sbomify.com/CVE-2024-44148/): Security feature bypass in macOS (critical 10.0)
- [CVE-2023-38586](https://insights.sbomify.com/CVE-2023-38586/): Security feature bypass in macOS (critical 10.0)
- [CVE-2023-40455](https://insights.sbomify.com/CVE-2023-40455/): Security feature bypass in macOS (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-20639 and fix it if it is affected.

What it is: CVE-2026-20639 is a high-severity vulnerability in Apple Macos, published on 25 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-20639 in the wild and no public exploit code.

Affected product: Apple Macos. 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-2026-20639/ (Markdown: https://insights.sbomify.com/CVE-2026-20639/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-20639
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-20639
- OSV: https://osv.dev/vulnerability/CVE-2026-20639

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-20639/
Summaries are generated and may contain mistakes; the official description above is the record.