CVE-2026-49177
MEDIUM 5.5 ALL-YEARSOut-of-bounds read in Windows TCP/IP allows an authorized attacker to disclose information locally.
No known exploitation, public exploit, or elevated probability at this time. Track for changes.
Exploitation likelihood
0.4%chance of exploitation in 30 days · 38th percentile
Impact if exploited
5.5CVSS 3.1 · MEDIUM · CNA
- ConfidentialityHigh
- IntegrityNone
- AvailabilityNone
What an attacker needs
- ⚠Access: Requires local access to the host
- ⚠Privileges: Requires a low-privilege account
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept
No public PoC is currently catalogued.
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Tracked sources are checked weekly for the full archive, including PoCs published after the original disclosure. A later release appears after a tracked source lists it and a refresh succeeds.
Affected
Vendors Microsoft
Products Windows 10 Version 1607 Windows 10 Version 1809 Windows 10 Version 21h2 Windows 10 Version 22h2 Windows 11 Version 24h2 Windows 11 Version 25h2 Windows 11 Version 26h1 Windows Server 2012 Windows Server 2012 (Server Core Installation) Windows Server 2012 R2 Windows Server 2012 R2 (Server Core Installation) Windows Server 2016 Windows Server 2016 (Server Core Installation) Windows Server 2019 Windows Server 2019 (Server Core Installation) Windows Server 2022 Windows Server 2025 Windows Server 2025 (Server Core Installation) Windows 10 1607 Windows 10 1809 Windows 10 21h2 Windows 10 22h2 Windows 11 24h2 Windows 11 25h2 Windows 11 26h1
Weakness (CWE)
- CWE-125: : Out-of-bounds Read
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C
References and research data (JSON)
Known Affected Software Configurations
| Vendor | Product | Version range |
|---|---|---|
| Microsoft | Windows 10 1607 | < 10.0.14393.9339 |
| Microsoft | Windows 10 1607 | < 10.0.14393.9339 |
| Microsoft | Windows 10 1809 | < 10.0.17763.9020 |
| Microsoft | Windows 10 1809 | < 10.0.17763.9020 |
| Microsoft | Windows 10 21h2 | < 10.0.19044.7548 |
| Microsoft | Windows 10 21h2 | < 10.0.19044.7548 |
| Microsoft | Windows 10 21h2 | < 10.0.19044.7548 |
| Microsoft | Windows 10 22h2 | < 10.0.19045.7548 |
| Microsoft | Windows 10 22h2 | < 10.0.19045.7548 |
| Microsoft | Windows 10 22h2 | < 10.0.19045.7548 |
| Microsoft | Windows 11 24h2 | < 10.0.26100.8875 |
| Microsoft | Windows 11 24h2 | < 10.0.26100.8875 |
| Microsoft | Windows 11 25h2 | < 10.0.26200.8875 |
| Microsoft | Windows 11 25h2 | < 10.0.26200.8875 |
| Microsoft | Windows 11 26h1 | < 10.0.28000.2269 |
| Microsoft | Windows 11 26h1 | < 10.0.28000.2525 |
| Microsoft | Windows Server 2012 | * |
| Microsoft | Windows Server 2012 | r2 |
| Microsoft | Windows Server 2016 | < 10.0.14393.9339 |
| Microsoft | Windows Server 2019 | < 10.0.17763.9020 |
| Microsoft | Windows Server 2022 | < 10.0.20348.5386 |
| Microsoft | Windows Server 2025 | < 10.0.26100.33158 |
All CVSS metrics
- MEDIUM 5.5 v3.1 · CNA Primary
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C - MEDIUM 5.5 v3.1 · NVD Secondary
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
References
Patches & mitigations
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-49177 CVE record · microsoft · Updated 2026-10-08T18:12:55.710Z
NVD · CVE-2026-49177 · Updated 2026-08-12T18:17:30.303
Advisories
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-43989 EUVD · EUVD-2026-43989
Technical & other
- https://www.talosintelligence.com/vulnerability_reports/TALOS-2026-2427CVE record · CVE · Updated 2026-08-12T17:20:16.553Z
NVD · CVE-2026-49177 · Updated 2026-08-12T18:17:30.303
Sources: NVD · CVE.org · All sources and attribution · EPSS