CVE-2026-68820: Microsoft Windows Ancillary Function Driver for WinSock Use-After-Free Vulnerability

What it is

Use after free in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.

Description quoted from the CVE record (assigned by microsoft, published 2026-08-11).

Weakness: CWE-416: Use After Free

How it can be exploited

Exploitable with local access with high attack complexity needing low privileges and no user interaction. Impact: confidentiality high, integrity high, availability high. CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

CISA assessment (SSVC): CISA assesses exploitation as active. Automatable: no. Technical impact: total.

On CISA KEV since

2026-08-11

US federal deadline

2026-08-25

Ransomware use

Not known

Public exploit evidence (Exploit Observer)

Also known as: BDU:2026-11398, EUVD-2026-56468, GHSA-c433-3382-mw5v

Exploit Observer links 2 pieces of public exploit code or detection modules that name this CVE or one of its aliases.

Exploit code and modules (2)

Code that names this CVE. A repository can be a working exploit, a scanner, a fake or malware; read it before running anything.

• Code repository: https://github.com/fevar54/cve-2026-68820-mitigation-poc-
• Code repository: https://github.com/maxprog-svg/cve-2026-68820_mass_exploit

Research and write-ups (3)

• Research or write-up: https://avleonov.com/2026/09/11/i153-about-elevation-of-privilege-windows-ancillary-function-driver-for-winsock-cve202668820-vulnerability
• Research or write-up: https://fidelissecurity.com/vulnerabilities/cve-2026-68820
• Research or write-up: https://ptsecurity.com/research/trending-vulnerabilities/CVE-2026-68820

Vulnerability databases and vendor advisories (6)

Catalogue entries, not exploit evidence.

• Vulnerability database or vendor advisory: https://euvd.enisa.europa.eu/enisa/EUVD-2026-56468
• Vulnerability database or vendor advisory: https://github.com/advisories/GHSA-c433-3382-mw5v
• Vulnerability database or vendor advisory: https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2026-68820
• Vulnerability database or vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-68820
• Vulnerability database or vendor advisory: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-68820
• Vulnerability database or vendor advisory: https://www.tenable.com/cve/CVE-2026-68820

7 more references returned by Exploit Observer did not name this CVE or an alias, so they are left out.

VEDAS data as of 2026-11-01T17:12 UTC; fetched 2026-11-02.

Live scores

EPSS

0.086
some chance of attack soon

VEDAS

0.531
some exploit evidence

On CISA KEV

Yes, since 2026-08-11

Detection rule

Out of scope (local)

Thin horizontal line: the “likely” (EPSS 0.10) or “strong” (VEDAS 0.90) threshold. Shaded “no data” areas are periods when cve-scores did not publish.

Who is affected

Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.

Exploit Observer also maps it to: microsoft windows_10_1607, microsoft windows_10_1809, microsoft windows_10_21h2, microsoft windows_10_22h2, microsoft windows_11_23h2, microsoft windows_11_24h2, microsoft windows_11_25h2, microsoft windows_11_26h1, microsoft windows_server_2012, microsoft windows_server_2016.

How to fix it

Fixed versions stated in the CVE record: 10.0.14393.9418, 10.0.17763.9121, 10.0.19044.7663, 10.0.19045.7663, 10.0.22631.7517, 10.0.26100.9168, 10.0.26200.9168, 10.0.28000.2704, 6.2.9200.26280, 6.3.9600.23338, 10.0.20348.5499, 10.0.26100.33296.

CISA required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset’s internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

Vendor guidance:

• Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability (vendor-advisory, patch)

How to detect it

This bug needs local access to exploit. VEDAS signatures cover remotely exploitable bugs for now, so there is no network rule or remote check for it. Patch it and watch your endpoint telemetry for unusual local activity.

Advisories on this CVE

• Windows AFD.sys use-after-free (CVE-2026-68820) (August 2026)

References

Vendor advisories and patches

• Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability (vendor-advisory, patch)

Government sources

• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-68820 (government-resource)

Other databases

• CVE record (cve.org)
• NVD
• Exploit Observer

Where this comes from

This advisory is generated automatically by VEDAS from: CVE.org record, CISA KEV, cve-scores (EPSS and VEDAS), Exploit Observer. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.