---
id: "CVE-2026-85897"
kind: "vulnerability"
aliases: ["CVE-2026-85897"]
title: "Microsoft Edge: heap buffer overflow lets a remote attacker run code"
severity: "high"
cvss: 8.8
epss: null
exploited: false
status: "open"
category: "other"
products: [{"name": "Microsoft Edge (Chromium-based)", "fixed": ["154.0.4258.37"], "affected": "< 154.0.4258.37", "ecosystem": "vendor"}]
ecosystems: []
tags: ["browser", "chromium", "microsoft-edge", "other", "windows"]
not_affected_if: ["patched-154.0.4258.37"]
published_at: "2026-10-29T16:19:45+00:00"
first_seen_at: "2026-10-29T16:26:01+00:00"
updated_at: "2026-10-29T16:35:44+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-85897", "first_seen_at": "2026-10-29T16:26:01+00:00"}, {"source": "analyst", "url": null, "first_seen_at": "2026-10-29T16:35:44+00:00"}]
---

# Microsoft Edge: heap buffer overflow lets a remote attacker run code

A heap-based buffer overflow in Microsoft Edge (Chromium-based) can be triggered by an unauthorized attacker over the network. The sources say this allows code execution.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:Microsoft Edge (Chromium-based) affected < 154.0.4258.37 fixed 154.0.4258.37

## How to check

Open edge://settings/help; if the version is below 154.0.4258.37 you are exposed. Fleet: compare installed msedge.exe file version against 154.0.4258.37.

## Fix

Update Microsoft Edge to 154.0.4258.37 or later (current stable 155.0.4283.62 per HKCERT/GovCERT.HK also covers it); edge://settings/help applies the update

## Timeline

- 2026-10-29T16:26:01+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-85897
- 2026-10-29T16:35:44+00:00 analyst — MSRC page read: heap overflow (CWE-122) in Edge, fixed in 154.0.4258.37 (Oct 16 2026), UI required (open crafted file/page), not exploited, not public, 'Exploitation Less Likely'. Later Edge 155.0.4283.62 also contains it.

## Documents

- [advisory] MSRC: CVE-2026-85897 Microsoft Edge (Chromium-based) RCE https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-85897

## From the sources

Heap-based buffer overflow in Microsoft Edge (Chromium-based) allows an unauthorized attacker to execute code over a network.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_