CVE-2026-20931Patch(microsoft / windows_10_1607)

HIGHCVSS 8.0 · HIGH

Exploitation ongoing with high activity in latest observed window (1 mentions)

Immediate actions

  • Patch microsoft windows_10_1607 systems immediately
  • Assume compromise if assets are exposed
  • Hunt for exploitation attempts and persistence artifacts

Recommended action window: Immediate (within 24h)

NVD description

External control of file name or path in Windows Telephony Service allows an authorized attacker to elevate privileges over an adjacent network.

6.5/ 10 priority

Sources & remediation

Weakness type (CWE)
CWE-73

Priority

HIGH

Exploitation

ACTIVE

PoC

NONE

Patch

AVAILABLE

Momentum

STABLE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

  • windows_10_1607
  • windows_10_1809
  • windows_10_21h2
  • windows_10_22h2

Threat summary

  • Active exploitation appears in 1 classified signals
  • Exploit tooling references are present in monitored signal
  • Patch or workaround signal is available
  • 3 mentions across 3 observed days

What's happening

  • Active exploitation reported across 1 signal
  • Exploit tool or code specified in 1 signal
  • Patch or workaround mentioned in 2 signals
  • Technical details provided in 1 signal
  • Peaked 2d ago at 1 mentions (2026-02-25); latest day: 1
  • 3 total mentions across 3 days

Affected systems

Vendors
Products
windows_10_1607windows_10_1809windows_10_21h2windows_10_22h2windows_11_23h2windows_11_24h2windows_11_25h2windows_server_2008windows_server_2012windows_server_2016

2 versions affected across 14 products

Deep dive

Activity timeline3 mentions / 3d
00111Mentions · 2026-02-25: 1Mentions · 2026-04-22: 1Mentions · 2026-04-25: 1Exploit Tool / Code · 2026-02-25: 1Active Exploitation · 2026-02-25: 1Patch / Workaround · 2026-04-22: 1Patch / Workaround · 2026-04-25: 1Technical Details · 2026-02-25: 102-2504-2204-25
Signal classification2 categories
Patch
266.7%
Active Exploitation
133.3%
Referenced assets27 URLs
Classification over time
DateTotalLabels
2026-02-251
Active Exploitation1
2026-04-221
Patch1
2026-04-251
Patch1
Full discourse3 posts
  • 0patch@0patch
    Patch

    Micropatches released for Windows Telephony Service Elevation of Privilege Vulnerability (CVE-2026-20931) https://blog.0patch.com/2026/04/micropatches-released-for-windows.html https://t.co/N3QIy0WU5P

    Post summary

    Micropatches have been released to address CVE-2026-20931, a Windows Telephony Service elevation‑of‑privilege vulnerability.

    11101942.1K
    8.4K followersView on X
  • Günter Born@etguenni
    Patch

    Windows Server Telephony Schwachstelle CVE-2026-20931 bekommt inoffiziellen 0patch Fix https://borncity.com/blog/2026/04/25/0patch-fix-fuer-windows-server-telephony-schwachstelle/

    Post summary

    The blog post announces an unofficial 0patch fix for the Windows Server Telephony vulnerability CVE‑2026‑20931, indicating an available workaround but no exploit details.

    00010295
    2.7K followersView on X
  • RST Cloud@rst_cloud
    Active Exploitation

    #threatreport #MediumCompleteness January 2026 CVE Landscape: 23 Critical Vulnerabilities Mark 5% Increase, APT28 Exploits Microsoft Office Zero-Day | 24-02-2026 Source: https://www.recordedfuture.com/blog/january-2026-cve-landscape Key details below ↓ 🧑‍💻Actors/Campaigns: Fancy_bear Neusploit 💀Threats: Nuclei_tool, Minidoor, Pixynetloader, Covenant_c2_tool, Grunt, Com_hijacking_technique, Supply_chain_technique, 🎯Victims: Enterprise communication platforms, Enterprise management platforms, Government users, Business users, Wordpress sites, Email systems 🏭Industry: Government 🌐Geo: Russian 🔓CVEs: CVE-2026-23760 \[[Vulners](https://vulners.com/cve/CVE-2026-23760)] - CVSS V3.1: *9.8*, - Vulners: Exploitation: True Soft: - smartertools smartermail (<100.0.9511) CVE-2025-34026 \[[Vulners](https://vulners.com/cve/CVE-2025-34026)] - CVSS V3.1: *7.5*, - Vulners: Exploitation: True Soft: - versa-networks concerto (<12.1.2, 12.2.0) CVE-2009-0556 \[[Vulners](https://vulners.com/cve/CVE-2009-0556)] - CVSS V3.1: *8.8*, - Vulners: Exploitation: True Soft: - microsoft office_powerpoint (2004) - microsoft powerpoint (2000, 2002, 2003) CVE-2025-8110 \[[Vulners](https://vulners.com/cve/CVE-2025-8110)] - CVSS V3.1: *8.8*, - Vulners: Exploitation: True Soft: - gogs (le0.13.3) CVE-2026-24423 \[[Vulners](https://vulners.com/cve/CVE-2026-24423)] - CVSS V3.1: *9.8*, - Vulners: Exploitation: True Soft: - smartertools smartermail (<100.0.9511) CVE-2025-68645 \[[Vulners](https://vulners.com/cve/CVE-2025-68645)] - CVSS V3.1: *8.8*, - Vulners: Exploitation: True Soft: - synacor zimbra_collaboration_suite (<10.0.18, <10.1.13) CVE-2018-14634 \[[Vulners](https://vulners.com/cve/CVE-2018-14634)] - CVSS V3.1: *7.8*, - Vulners: Exploitation: True Soft: - paloaltonetworks pan-os (<7.1.23, <8.0.16, <8.1.7) CVE-2026-21509 \[[Vulners](https://vulners.com/cve/CVE-2026-21509)] - CVSS V3.1: *7.8*, - Vulners: Exploitation: True Soft: - microsoft 365_apps (-) - microsoft office (2016, 2019) - microsoft office_long_term_servicing_channel (2021, 2024) CVE-2025-37164 \[[Vulners](https://vulners.com/cve/CVE-2025-37164)] - CVSS V3.1: *10.0*, - Vulners: Exploitation: True Soft: - hpe oneview (le10.20.00) CVE-2026-1340 \[[Vulners](https://vulners.com/cve/CVE-2026-1340)] - CVSS V3.1: *9.8*, - Vulners: Exploitation: True Soft: - ivanti endpoint_manager_mobile (le12.7.0.0) CVE-2026-1281 \[[Vulners](https://vulners.com/cve/CVE-2026-1281)] - CVSS V3.1: *9.8*, - Vulners: Exploitation: True Soft: - ivanti endpoint_manager_mobile (le12.5.0.0, 12.5.1.0, 12.6.0.0, 12.6.1.0, 12.7.0.0) CVE-2026-20045 \[[Vulners](https://vulners.com/cve/CVE-2026-20045)] - CVSS V3.1: *9.8*, - Vulners: Exploitation: True Soft: - cisco unified_communications_manager (<14su5, le15su3a) - cisco unified_communications_manager_im_and_presence_service (<14su5, le15su3a) - cisco unity_connection (<14su5, le15su3) CVE-2026-20931 \[[Vulners](https://vulners.com/cve/CVE-2026-20931)] - CVSS V3.1: *8.0*, - Vulners: Exploitation: Unknown Soft: - microsoft windows_10_1607 (<10.0.14393.8783) - microsoft windows_10_1809 (<10.0.17763.8276) - microsoft windows_10_21h2 (<10.0.19044.6809) - microsoft windows_10_22h2 (<10.0.19045.6809) ... CVE-2026-20805 \[[Vulners](https://vulners.com/cve/CVE-2026-20805)] - CVSS V3.1: *5.5*, - Vulners: Exploitation: True Soft: - microsoft windows_10_1607 (<10.0.14393.8783) - microsoft windows_10_1809 (<10.0.17763.8276) - microsoft windows_10_21h2 (<10.0.19044.6809) - microsoft windows_10_22h2 (<10.0.19045.6809) ... CVE-2025-52691 \[[Vulners](https://vulners.com/cve/CVE-2025-52691)] - CVSS V3.1: *10.0*, - Vulners: Exploitation: True Soft: - smartertools smartermail (<100.0.9413) CVE-2025-31125 \[[Vulners](https://vulners.com/cve/CVE-2025-31125)] - CVSS V3.1: *7.5*, - Vulners: Exploitation: True Soft: - vitejs vite (<4.5.11, <5.4.16, <6.0.13, <6.1.3, <6.2.4) CVE-2026-24858 \[[Vulners](https://vulners.com/cve/CVE-2026-24858)] - CVSS V3.1: *9.8*, - Vulners: Exploitation: True Soft: - fortinet fortianalyzer (le7.0.15, le7.2.11, <7.4.10, <7.6.6) - fortinet fortimanager (le7.0.15, le7.2.11, <7.4.10, <7.6.6) - fortinet fortiproxy (le7.0.22, le7.2.15, le7.4.12, le7.6.4) - fortinet fortiweb (le7.4.11, le7.6.6, le8.0.3) ... CVE-2025-54313 \[[Vulners](https://vulners.com/cve/CVE-2025-54313)] - CVSS V3.1: *7.5*, - Vulners: Exploitation: True Soft: - prettier eslint-config-prettier (8.10.1, 9.1.1, 10.1.6, 10.1.7) CVE-2025-40551 \[[Vulners](https://vulners.com/cve/CVE-2025-40551)] - CVSS V3.1: *9.8*, - Vulners: Exploitation: True Soft: - solarwinds web_help_desk (<2026.1) CVE-2026-20029 \[[Vulners](https://vulners.com/cve/CVE-2026-20029)] - CVSS V3.1: *4.9*, - Vulners: Exploitation: Unknown CVE-2026-23550 \[[Vulners](https://vulners.com/cve/CVE-2026-23550)] - CVSS V3.1: *10.0*, - Vulners: Exploitation: Unknown CVE-2026-23800 \[[Vulners](https://vulners.com/cve/CVE-2026-23800)] - CVSS V3.1: *10.0*, - Vulners: Exploitation: Unknown CVE-2024-37079 \[[Vulners](https://vulners.com/cve/CVE-2024-37079)] - CVSS V3.1: *9.8*, - Vulners: Exploitation: True Soft: - vmware cloud_foundation (<5.2) CVE-2026-24061 \[[Vulners](https://vulners.com/cve/CVE-2026-24061)] - CVSS V3.1: *9.8*, - Vulners: Exploitation: True Soft: - gnu inetutils (le2.7) 🤖LLM extracted TTPs:` T1005, T1027, T1053.005, T1071.001, T1078, T1090, T1098, T1112, T1114.003, T1133, ... 🧨IOCs: - Path: 2 - Registry: 1 - IP: 6 - Email: 4 - File: 2 💽Software: Microsoft Office, Ivanti, Linux, Zimbra Collaboration Suite, WordPress, Outlook, Ivanti EPMM 🔢Algorithms: xor 📜Programming Languages: php #threatreport: In January 2026, there was a noted 5% increase in critical vulnerabilities, with 23 high-impact issues identified. Among these, the exploitation of a significant Microsoft Office zero-day vulnerability (CVE-2026-21509) by Russian state-sponsored group APT28 highlighted ongoing threats to enterprise technologies. This vulnerability, which relates to the reliance on untrusted inputs in security decisions, enabled APT28 to utilize weaponized Rich Text Format (RTF) files to deliver various malicious implants, including MiniDoor, PixyNetLoader, and Covenant Grunt. The exploitation chain initiated with an RTF file that bypassed Office OLE mitigations. The attackers deployed MiniDoor as an Outlook VBA script for email collection, while PixyNetLoader, which created a mutex for persistence, allowed further attacks. A notable aspect of this operation was the use of geography-based evasion to limit the delivery of the malicious payloads, demonstrating the sophistication of the APT28 attacks. In addition to Microsoft, other vendors such as SmarterTools and Ivanti were significantly affected, with SmarterTools reporting multiple critical vulnerabilities allowing authentication bypass and remote code execution (RCE). Specifically, CVE-2026-23760 identified a privilege escalation flaw in SmarterMail, permitting unauthenticated users to reset passwords, demonstrating serious flaws in expected security protocols. Furthermore, the Modular DS WordPress plugin was found to have multiple vulnerabilities, CVE-2026-23550 and CVE-2026-23800, that allowed attackers to gain administrator access without authentication. These vulnerabilities emphasize the risk of widespread exploitation due to the centralized management of multiple WordPress sites.

    Post summary

    The report details active exploitation of multiple critical CVEs, notably CVE‑2026‑21509, by APT28 using weaponized RTF files and associated tools, highlighting ongoing threats to enterprise systems.

    0000074
    589 followersView on X
CPE platform detail19 entries

19 of 19 entries

PartVendorProductVersionTarget SWTarget HW
OSmicrosoftwindows_10_1607--x64
OSmicrosoftwindows_10_1607--x86
OSmicrosoftwindows_10_1809--x64
OSmicrosoftwindows_10_1809--x86
OSmicrosoftwindows_10_21h2---
OSmicrosoftwindows_10_22h2---
OSmicrosoftwindows_11_23h2---
OSmicrosoftwindows_11_24h2---
OSmicrosoftwindows_11_25h2---
OSmicrosoftwindows_server_2008--x64
OSmicrosoftwindows_server_2008--x86
OSmicrosoftwindows_server_2008r2-x64
OSmicrosoftwindows_server_2012---
OSmicrosoftwindows_server_2012r2--
OSmicrosoftwindows_server_2016---
OSmicrosoftwindows_server_2019---
OSmicrosoftwindows_server_2022---
OSmicrosoftwindows_server_2022_23h2---
OSmicrosoftwindows_server_2025---

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