CVE-2026-84810

Antivirus skips script files, only scans SKILL.md, allowing malicious code to pass safe.

• CVSS 7.1
• 693
• Input Validation and Sanitization
• Local

claude-skill-antivirus fails to analyze executable files when scanning local skill directories, reading only SKILL.md while ignoring Python source, bytecode, and other artifacts in the scripts directory. Attackers can distribute skills with malicious code in non-manifest files that receive a SAFE verdict with 100/100 trust score despite containing unanalyzed executable payloads.

CVE

CVE-2026-84810

CWE

693

CVSS base score

7.1

Published

2026-09-02

OWASP

A08 Software and Data Integrity Failures

Orthogonal defect classification

Checking

Code defect classification

Missing Check

Category

Input Validation and Sanitization

Subcategory

Insecure Parsing or Deserialization

Accessibility scope

Local

Impact

Arbitrary Code Execution

Affected component

Python

Solution

Upgrade the claude‑skill‑antivirus package to version 2.4.1 or later, which adds recursive scanning of all files in the scripts directory (including *.py, *.pyc and other executables) and enforces full analysis before assigning a SAFE verdict.

import os

def scan_skill_dir(skill_path):
    """Return list of files considered safe."""
    safe_files = []
    manifest_path = os.path.join(skill_path, "SKILL.md")
    # VULNERABLE: only reads manifest, ignores other executable artifacts
    if os.path.isfile(manifest_path):
        with open(manifest_path, "r", encoding="utf-8") as f:
            for line in f:
                if line.strip().endswith(".py"):
                    safe_files.append(line.strip())
    return safe_files

import os

def scan_skill_dir(skill_path):
    """Return list of files considered safe."""
    safe_files = []
    manifest_path = os.path.join(skill_path, "SKILL.md")
    # FIX: include all script files, not just those listed in manifest
    for root, _, files in os.walk(skill_path):
        for name in files:
            if name.endswith(('.py', '.pyc', '.pyo')):
                safe_files.append(os.path.join(root, name))
    return safe_files

__VAITP_MODEL_REFUSED__

@misc{vaitp:cve202684810,
  title        = {{Antivirus skips script files, only scans SKILL.md, allowing malicious code to pass safe.}},
  author       = {Bogaerts, Fr\'ed\'eric and Ivaki, Naghmeh and Fonseca, Jos\'e},
  year         = {2026},
  note         = {VAITP Python Vulnerability Dataset, entry CVE-2026-84810},
  howpublished = {\url{https://netpack.pt/vaitp/vulnerability/CVE-2026-84810/}}
}