# CVE-2026-85899: Microsoft Edge use-after-free privilege escalation

Source: https://junglewise.ai/threats/cve-2026-85899-use-after-free-in-microsoft-edge-chromium-based-allows-an  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-29. Updated: 2026-10-29  
License: CC BY 4.0 with a link back

CVE-2026-85899 · Severity: high · CVSS 8.1 · Published 2026-10-29

Microsoft Edge is a web browser used by millions of users globally. A use-after-free vulnerability allows an authorized attacker to elevate their privileges on a user's system through a network-based attack. This could enable an attacker to gain higher-level access to sensitive data or compromise system integrity.

Technologies: [Microsoft Edge](https://junglewise.ai/threats/technologies/edge). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-85899 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-85899 being exploited in the wild.

**How severe is CVE-2026-85899?** High severity, with a CVSS score of 8.1, published 29 October 2026.

**Which products and versions are affected?** Microsoft Edge <UNKNOWN>.

**Is there a fix for CVE-2026-85899?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-85899 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-85899?** Check whether you run Microsoft Edge 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.

## Technical details

A use-after-free vulnerability exists in Microsoft Edge (Chromium-based), allowing an authorized attacker to elevate privileges over the network. The vulnerability requires prior authorization and network access to exploit. Successful exploitation grants elevated privileges on the affected system.

## Affected products

- Microsoft Edge <UNKNOWN>

## Timeline

- 2026-10-29: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-85899](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-85899)

## Related threats

- [Microsoft Edge out-of-bounds read information disclosure](https://junglewise.ai/threats/cve-2026-122518-out-of-bounds-read-in-microsoft-edge-chromium-based-allows-an)
- [Microsoft Edge privilege escalation via incorrect authorization](https://junglewise.ai/threats/cve-2026-69446-incorrect-authorization-in-microsoft-edge-chromium-based-allows)
- [Microsoft Edge use-after-free privilege elevation](https://junglewise.ai/threats/cve-2026-96203-use-after-free-in-microsoft-edge-chromium-based-allows-an)
- [Microsoft Edge heap-based buffer overflow](https://junglewise.ai/threats/cve-2026-96199-heap-based-buffer-overflow-in-microsoft-edge-chromium-based)
- [Microsoft Edge heap-based buffer overflow](https://junglewise.ai/threats/cve-2026-96198-heap-based-buffer-overflow-in-microsoft-edge-chromium-based)