# CVE-2026-65400: Apple macOS Improper Authentication

> An attacker on the network can authenticate to Screen Sharing without valid credentials due to an authentication issue in macOS.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Yes, since 18 Aug 2026 (CISA KEV)
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 6 Aug 2026
- **Updated:** 26 Oct 2026
- **Also known as:** GHSA-cwph-f4w9-f4wq

## What is CVE-2026-65400?

CVE-2026-65400 is a critical authentication bypass vulnerability in Apple Macos, published on 6 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An authentication issue was addressed with improved state management. This issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.7.9, macOS Sonoma 14.8.9, macOS Tahoe 26.6.1, macOS Tahoe 26.7. An attacker on the network may be able to authenticate to Screen Sharing without valid credentials.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2026-65400?

It affects 1 product.


Products: Apple Macos.

## How do I fix CVE-2026-65400?

No fix has been published for CVE-2026-65400 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 21 Aug 2026.

## Is CVE-2026-65400 being exploited?

Yes. Attackers have exploited CVE-2026-65400 in the wild since at least 18 Aug 2026.

Public exploit code:

- Read-only PoC for CVE-2026-65400 — macOS Screen Sharing (screensharingd) pre-auth SRP bypass giving root file read. Patched in macOS 26.6.1 / 15.7.9 / 14.8.9. (github_poc): https://github.com/panchocosil/CVE-2026-65400-poc
- Apple MacOS Screen Sharing Arbitrary File read/write -> RCE (github_poc): https://github.com/acheong08/CVE-2026-65400
- CVE-2026-65400 (github_poc): https://github.com/HORKimhab/CVE-2026-65400

## Other vulnerabilities in Apple Macos

- [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)
- [CVE-1999-0590](https://insights.sbomify.com/CVE-1999-0590/): Other in n/a (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-65400 and fix it if it is affected.

What it is: CVE-2026-65400 is a critical authentication bypass vulnerability in Apple Macos, published on 6 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2026-65400 in the wild since at least 18 Aug 2026.

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-2026-65400/ (Markdown: https://insights.sbomify.com/CVE-2026-65400/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-65400
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-65400
- OSV: https://osv.dev/vulnerability/CVE-2026-65400

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-65400/
Summaries are generated and may contain mistakes; the official description above is the record.