High · CVSS 7.7CVE-2026-8618

Pre-Authentication Stack-based Buffer Overflow Remote Code Execution in TDDPv2 Subtype 0x91 on Deco M9 Plus

Answer in brief

CVE-2026-8618 records a High severity (CVSS 7.7) vulnerability in Pre-Authentication Stack-based Buffer Overflow Remote Code Execution in TDDPv2 Subtype 0x91 on Deco M9 Plus. The current sources do not mark it as known exploited. The current feed maps TP-Link Systems Inc./Deco M9 Plus V2 (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 1, 2026Updated Oct 1, 2026Source checked Oct 1, 2026First seen by HOL Oct 1, 2026Material review Oct 1, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.7
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 7.7. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps TP-Link Systems Inc./Deco M9 Plus V2 (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
TP-Link Systems Inc./Deco M9 Plus V2generic	>=0 <1.9.2 Build 20260818	1.9.2 Build 20260818, 1.9.2

Recommended response

Check inventory. Check lockfiles and deployed manifests for TP-Link Systems Inc./Deco M9 Plus V2.
Review the reported fix. Update TP-Link Systems Inc./Deco M9 Plus V2 to 1.9.2 Build 20260818 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Oct 1, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 1, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 1, 2026

Sources and claim methodology

Upstream source description

A stack-based buffer overflow vulnerability exists in the TDDPv2 service (/usr/bin/tddp) on Deco M9 Plus due to insufficient validation of decrypted request data length before it is copied into a fixed-size stack buffer in the subtype 0x91 handler. Successful exploitation may allow an adjacent, unauthenticated attacker to cause a denial of service or achieve arbitrary code execution during the device setup phase through crafted TDDP packets.

Quoted source text, attributed separately from HOL analysis.