CVE-2026-85818
Improper verification of cryptographic signature in Windows Schannel allows an unauthorized…
- Risk score
- 76/100
- CVSS
- 9.0 v3.1
- Exploit chance (30 days)
- 0.4%
- Published
- 13 Oct 2026
Open in the live forecast Today's forecast
What to know
- What it is
- Improper verification of cryptographic signature in Windows Schannel allows an unauthorized attacker to perform spoofing over a network.
- Affected
- Microsoft Windows 11 23h2
- Fix
- Apply the vendor's security update; see the linked advisory.
- Exploitation
- No known exploitation
Story map
At a glance
Microsoft Windows 11 23h2: Red, act today. Use after free in Microsoft QUIC allows an unauthorized attacker to execute code over a network.
The flaws
- CVE-2026-85818: Improper verification of cryptographic signature in Windows Schannel allows an unauthorized… (CVSS 9.0 · EPSS 0%)
- CVE-2026-100219: Use-after-free (CVSS 9.8 · EPSS 1%)
- CVE-2026-96909: Heap buffer overflow (CVSS 9.8 · EPSS 1%)
- CVE-2026-83855: Integer underflow (wrap or wraparound) in Windows WLAN Service allows an unauthorized attacker to… (CVSS 7.5 · EPSS 1%)
The fix
Fix: Apply the vendor's security update; see the linked advisory.
Who is exposed: Microsoft Windows 11 23h2
Where it stands
- No known exploitation
Connects to
- Same weakness: CWE-347 (CWE-347). 68 other warnings in 30 days
- Same product: Earlier Microsoft Windows 11 23h2 warnings. 31 in the last 90 days
Why it is Amber
- CVSS 9.0 critical
- Remotely exploitable without logging in
- On your watchlist: windows server
References
Original description
Improper verification of cryptographic signature in Windows Schannel allows an unauthorized attacker to perform spoofing over a network.
Last activity 13 Oct 2026. Patch Forecast updates every hour.