7.1
HIGH CVSS 4.0
CVE-2026-84809
Tencent AI-Infra-Guard Remote Code Execution via Malicious Python Bytecode Injection
Description

Tencent AI-Infra-Guard's skill-scan component excludes compiled Python bytecode files from analysis by hardcoding __pycache__ directories and .pyc/.pyo/.pyd extensions into skip lists across multiple scanning surfaces. Attackers can distribute skills with benign Python source files alongside malicious compiled bytecode that executes on import while the scanner reports a safe verdict, enabling code execution when operators install the skill.

INFO

Published Date :

Sept. 2, 2026, 5:18 p.m.

Last Modified :

Sept. 2, 2026, 5:18 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-84809 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM [email protected]
CVSS 4.0 HIGH [email protected]
Solution
Scan compiled bytecode and ensure all executable code is analyzed.
  • Update scanner to include __pycache__ directories.
  • Scan .pyc, .pyo, and .pyd files.
  • Verify all imported code is analyzed.
  • Remove hardcoded skip lists for bytecode.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-84809 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-84809 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-84809 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-84809 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Sep. 02, 2026

    Action Type Old Value New Value
    Added Description Tencent AI-Infra-Guard's skill-scan component excludes compiled Python bytecode files from analysis by hardcoding __pycache__ directories and .pyc/.pyo/.pyd extensions into skip lists across multiple scanning surfaces. Attackers can distribute skills with benign Python source files alongside malicious compiled bytecode that executes on import while the scanner reports a safe verdict, enabling code execution when operators install the skill.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
    Added CWE CWE-693
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/84xxx/CVE-2026-84809.json">CVE-2026-84809</a>
    Added Reference https://github.com/Tencent/AI-Infra-Guard
    Added Reference https://github.com/Tencent/AI-Infra-Guard/blob/v4.6.0/skill-scan/skill_scan/tools/dir/dir_actions.py
    Added Reference https://github.com/Tencent/AI-Infra-Guard/blob/v4.6.0/skill-scan/skill_scan/utils/pre_scan.py
    Added Reference https://github.com/Tencent/AI-Infra-Guard/commit/7e0f749e3c023e5c6ab7b32fe97b3f6f2e8aeb04
    Added Reference https://github.com/Tencent/AI-Infra-Guard/issues/531
    Added Reference https://www.vulncheck.com/advisories/tencent-ai-infra-guard-skill-scan-analysis-bypass-via-excluded-python-bytecode
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.