Microsoft Edge is a widely used browser; a privilege-escalation bug from a major vendor can impact many organizations and merits broad IT distribution.
CVE-2026-85899
Use-after-free in Microsoft Edge allows privilege escalation.
Is CVE-2026-85899 being exploited?
Not confirmed. CVE-2026-85899 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked.
How severe is CVE-2026-85899?
CVE-2026-85899 is rated High with a CVSS score of 8.1. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-85899?
Yes. A fix has been recorded for CVE-2026-85899. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-85899 affect?
CVE-2026-85899 affects Microsoft Edge (Chromium-based), Windows systems running affected Edge versions. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-85899?
Install Microsoft Edge security update immediately
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Authorized attacker can exploit an Edge use-after-free to escape the browser sandbox and gain elevated/system privileges.
Patch when possible
- affected>= 1.0.0.0 and < 155.0.4283.45
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.