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CVE-2026-85880

HIGH 7.8 KNOWN EXPLOITED ALL-YEARS

Published 2026-09-08 · Last modified 2026-10-14 · microsoft · NVD: Analyzed

Heap-based buffer overflow in Windows ALPC allows an authorized attacker to elevate privileges locally.

ACTIVELY EXPLOITED

Confirmed exploited in the wild — in CISA KEV since 2026-09-08. Patch or mitigate now.

Exploitation likelihood

0.4%chance of exploitation in 30 days · 33rd percentile

● In CISA KEV (2026-09-08)○ Catalogued PoC◆ SSVC: exploitation active, automatable no

Impact if exploited

7.8CVSS 3.1 · HIGH · CNA

ConfidentialityHigh
IntegrityHigh
AvailabilityHigh

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.

Search for new PoCs

Search GitHub now — results may be empty or unverified.

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 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 10 1607 Windows 10 1809 Windows 10 21h2 Windows 10 22h2

Weakness (CWE)

CWE-122: : Heap-based Buffer Overflow
CWE-908: : Use of Uninitialized Resource

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C

References and research data (JSON)

Additional exploitation reports

Source-specific reports, separate from CISA KEV. Repeated observations from one source are not independent confirmations.

VulnCheck KEV · 2026-09-08T00:00:00Z
Source guidance: 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.
Source ransomware assessment: Unknown
VulnCheck KEV · CVE-2026-85880 · Updated 2026-09-08T00:00:00Z
VulnCheck KEV · 2026-09-08T00:00:00ZVulnCheck KEV · CVE-2026-85880
VulnCheck KEV · CVE-2026-85880
VulnCheck KEV · CVE-2026-85880
VulnCheck KEV · CVE-2026-85880
VulnCheck KEV · 2026-09-09T00:00:00ZVulnCheck KEV · CVE-2026-85880
VulnCheck KEV · CVE-2026-85880
VulnCheck KEV · 2026-09-14T00:00:00ZVulnCheck KEV · CVE-2026-85880
VulnCheck KEV · 2026-09-21T00:00:00ZVulnCheck KEV · CVE-2026-85880

Known Affected Software Configurations

Vendor	Product	Version range
Microsoft	Windows 10 1607	< 10.0.14393.9512
Microsoft	Windows 10 1607	< 10.0.14393.9512
Microsoft	Windows 10 1809	< 10.0.17763.9245
Microsoft	Windows 10 1809	< 10.0.17763.9245
Microsoft	Windows 10 21h2	< 10.0.19044.7725
Microsoft	Windows 10 21h2	< 10.0.19044.7725
Microsoft	Windows 10 21h2	< 10.0.19044.7725
Microsoft	Windows 10 22h2	< 10.0.19045.7725
Microsoft	Windows 10 22h2	< 10.0.19045.7725
Microsoft	Windows 10 22h2	< 10.0.19045.7725
Microsoft	Windows Server 2012	*
Microsoft	Windows Server 2012	r2
Microsoft	Windows Server 2016	< 10.0.14393.9512
Microsoft	Windows Server 2019	< 10.0.17763.9245
Microsoft	Windows Server 2022	< 10.0.20348.5622

All CVSS metrics

HIGH 7.8 v3.1 · CNA Primary
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C
HIGH 7.8 v3.1 · NVD Secondary
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References

Patches & mitigations

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-85880 vendor-advisorypatchPatchVendor AdvisoryKEV reportCVE record · microsoft · Updated 2026-10-14T23:09:31.608Z
NVD · CVE-2026-85880 · Updated 2026-09-24T23:19:20.773
VulnCheck KEV · CVE-2026-85880 · Updated 2026-09-08T00:00:00Z

Advisories

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-85880 government-resourceUS Government ResourceCVE record · CISA-ADP · Updated 2026-09-09T04:27:01.173Z
NVD · CVE-2026-85880 · Updated 2026-09-24T23:19:20.773
https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-73365 ADVISORYEUVD · EUVD-2026-73365
https://vulncheck.com/kev ADVISORYVulnCheck KEV · CVE-2026-85880 · Updated 2026-09-08T00:00:00Z

Technical & other

https://api.msrc.microsoft.com/cvrf/v3.0/cvrf/2026-Sep KEV reportVulnCheck KEV · CVE-2026-85880 · Updated 2026-09-08T00:00:00Z
https://euvd.enisa.europa.eu/enisa/EUVD-2026-73365 KEV reportVulnCheck KEV · CVE-2026-85880 · Updated 2026-09-08T00:00:00Z
https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json KEV reportVulnCheck KEV · CVE-2026-85880 · Updated 2026-09-08T00:00:00Z
https://docs.google.com/spreadsheets/d/1lkNJ0uQwbeC1ZTRrxdtuPLCIl7mlUreoKfSIgajnSyY/edit KEV reportVulnCheck KEV · CVE-2026-85880 · Updated 2026-09-08T00:00:00Z
https://www.volexity.com/blog/2026/09/09/mind-the-patch-gap-multiple-chinese-threat-actors-chain-0-day-exploits-in-chrome-windows/ KEV reportVulnCheck KEV · CVE-2026-85880 · Updated 2026-09-08T00:00:00Z
https://www.proofpoint.com/us/blog/threat-insight/once-bluemoon-multiple-state-aligned-threat-actors-rapidly-adopt-novel-exploit KEV reportVulnCheck KEV · CVE-2026-85880 · Updated 2026-09-08T00:00:00Z
https://www.volexity.com/blog/2026/09/21/mind-the-patch-gap-part-2-fake-websites-used-to-deploy-chrome-windows-0-day-exploits/ KEV reportVulnCheck KEV · CVE-2026-85880 · Updated 2026-09-08T00:00:00Z

Sources: NVD · CVE.org · All sources and attribution · EPSS