Cyber Resilience

CVE-2026-23565

Memory Safety in Teamviewer Digital Employee Experience ≤ 26.1

Published
29 January 2026
Modified
11 February 2026
Patch / advisory
CVSS Score v3.1 6.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0017 6th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-23565 is a medium-severity NULL Pointer Dereference (CWE-476) vulnerability in Teamviewer Digital Employee Experience. Its CVSS base score is 6.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 6th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and SC-7 (Boundary Protection) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

A vulnerability in TeamViewer DEX Client (former 1E Client) - Content Distribution Service (NomadBranch.exe) prior version 26.1 for Windows allows an attacker on the adjacent network to cause the NomadBranch.exe process to terminate via crafted requests. This can result in…

more

a denial-of-service condition of the Content Distribution Service.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
Why these techniques?

Null dereference in network-facing service directly enables remote DoS via crafted requests (T1499.004 Application or System Exploitation).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2025-69624Same product: Microsoft Windows
CVE-2024-1443Same product: Microsoft Windows
CVE-2025-66769Same product: Microsoft Windows
CVE-2026-21288Same product: Microsoft Windows
CVE-2026-8035Same product: Microsoft Windows
CVE-2026-3776Same product: Microsoft Windows
CVE-2026-32071Same vendor: Microsoft
CVE-2026-42903Same vendor: Microsoft
CVE-2026-34339Same vendor: Microsoft
CVE-2026-25168Same vendor: Microsoft

Affected Assets

teamviewer
digital employee experience
≤ 26.1

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-10 Information Input Validation
  • SC-7 Boundary Protection
Detect
Catch it (NIST detect / respond)
  • SI-4 System Monitoring
Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

prevent

Input validation on network requests directly prevents malformed data from triggering the NULL pointer dereference in NomadBranch.exe.

prevent

Boundary protection restricts adjacent-network traffic to only authorized endpoints, limiting exposure to crafted DoS requests.

detect

System monitoring can identify anomalous request patterns targeting the Content Distribution Service before or during exploitation.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices (static analysis, code review, safe coding standards) directly prevent NULL dereference bugs during development.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

detects

Security testing can detect NULL dereference defects before release.

prevents

Secure SDLC mandates defensive coding practices that can prevent NULL dereferences.

prevents

Application security requirements can specify input validation and pointer-safety rules.

prevents

Secure architecture principles encourage defensive design that avoids unsafe pointer use.

prevents

Secure coding standards directly require NULL-pointer checks and safe dereference patterns.

References