🛡️ CVE-2026-42904 — windows-10-21h2
Description
Heap-based buffer overflow in Windows TCP/IP allows an unauthorized attacker to elevate privileges over an adjacent network.
How this vulnerability can be exploited
This issue can be reached from an adjacent network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is changed, meaning a successful attack can affect components beyond the vulnerable one. Rated impact: confidentiality high, integrity high, availability high.
Weakness class
CVE-2026-42904 is classified as CWE-122: Heap-based Buffer Overflow. A write past the end of a heap allocation corrupts allocator metadata or neighbouring objects.
Affected software and timeline
Affected software: unknown, windows-10-21h2 (fixed in 10.0.19044.7417), windows-10-22h2 (fixed in 10.0.19045.7417), windows-11-23h2 (fixed in 10.0.22631.7219), windows-11-24h2 (fixed in 10.0.26100.8655), windows-11-25h2 (fixed in 10.0.26200.8655), windows-11-26h1 (fixed in 10.0.28000.2269), windows-server-2022 (fixed in 10.0.20348.5256) and windows-server-2025 (fixed in 10.0.26100.32995). Published on 9 June 2026. No public exploit is currently recorded for this entry. Record sourced from NVD.
References
Details
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Affected Packages
| Software | From version | Fixed in |
|---|---|---|
| unknown | — | — |
| windows-10-21h2 | — | 10.0.19044.7417 |
| windows-10-22h2 | — | 10.0.19045.7417 |
| windows-11-23h2 | — | 10.0.22631.7219 |
| windows-11-24h2 | — | 10.0.26100.8655 |
| windows-11-25h2 | — | 10.0.26200.8655 |
| windows-11-26h1 | — | 10.0.28000.2269 |
| windows-server-2022 | — | 10.0.20348.5256 |
| windows-server-2025 | — | 10.0.26100.32995 |
Similar Threats
- Unknown CVE-2022-0003
- Unknown CVE-2022-0303
- High CVE-2022-1206
- Unknown CVE-2022-0931
- Unknown CVE-2022-0094
Exploit Protection
Are you running windows-10-21h2?
CVE-2026-42904 carries CVSS 9.6 Critical rating. BotEraser checks your installation against this and other known CVE records, and blocks IPs associated with exploit activity.
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