TI-2026-18988 Aliases CVE-2026-23567 GHSA-5c5v-ch87-qh4m

Integer underflow in Content Distribution Service UDP handler

LOW 29CWE-122Published 2026-01-29 · Updated 2026-01-29

Key facts

Attack vector: Adjacent network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-122 and the CVSS impact.

Summary

An integer underflow in the UDP command handler of the TeamViewer DEX Client (former 1E Client) - Content Distribution Service (NomadBranch.exe) prior version 26.1 for Windows allows an adjacent network attacker to trigger a heap-based buffer overflow and cause a denial-of-service (service crash) via specially crafted UDP packets.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00352 29th percentileScored 2026-11-07

Fix Fixed DEX (TeamViewer): 26.1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
TeamViewer	DEX	before 26.1	26.1	Patch available	CNA

DEX VendorTeamViewer Affected before 26.1 Fixed in 26.1 Patch available CNA

CPE configurations NVD · 2

CPE	Versions	Role	Vendor
cpe:2.3:a:teamviewer:digital_employee_experience::::::::	before 26.1	Vulnerable	TeamViewer
cpe:2.3:o:microsoft:windows:-:::::::*	not specified by NVD	Running on	Microsoft

cpe:2.3:a:teamviewer:digital_employee_experience:*:*:*:*:*:*:*:* Versions before 26.1 Vulnerable ·TeamViewer
cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Microsoft

Remediation

Fix · CNA DEX (TeamViewer) Fixed in 26.1

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

Release · 2026-01-29
TeamViewer DEX 26.1
8 records Highest priority Priority LOW 8 LOW
Other records, highest priority first
- TI-2026-18989 Out-of-bounds read vulnerability in Content Distribution ServicePriority LOW 35
- TI-2026-18990 Out-of-bounds read vulnerability in Content Distribution ServicePriority LOW 33
- TI-2026-18984 Privilege escalation in TeamViewer DEX via DeleteFileByPath instructionPriority LOW 31
Show all 8 records →

Timeline

2026-10-02 Threatist record created from CVE-2026-23567
2026-10-03 Alias added: GHSA-5c5v-ch87-qh4m

References

Advisory 1

https://www.teamviewer.com/en/resources/trust-center/security-bulletins/tv-2026-1001/

TI-2025-28565 File Hash Validation Bypass in NomadBranch.exe CVSS 3.1HIGH 8.8
TI-2025-40180 Command Injection in 1E-Explorer-TachyonCore-FindFileBySizeAndHash Instruction CVSS 3.1HIGH 7.2
TI-2025-40179 Command Injection in 1E-Nomad-GetCmContentLocations Instruction CVSS 3.1HIGH 7.2
TI-2025-40178 Command Injection in 1E-Explorer-TachyonCore-CheckSimpleIoC Instruction CVSS 3.1HIGH 7.2
TI-2025-40177 Command Injection in 1E-Explorer-TachyonCore-DevicesListeningOnAPort Instruction CVSS 3.1HIGH 7.2
TI-2026-18989 Out-of-bounds read vulnerability in Content Distribution Service CVSS 3.1HIGH 8.1

See all 21 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences