PatchSiren cyber security CVE debrief
CVE-2026-84809 Tencent CVE debrief
AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-09-02T17:18:05.150Z and has not been modified since then. Tencent AI-Infra-Guard's skill-scan component vulnerability allows attackers to distribute skills with benign Python source files alongside malicious compiled bytecode that executes on import. Operators and administrators should review and update skill-scan component configurations to ensure comprehensive analysis of skills. The CVE record indicates that the skill-scan component excludes compiled Python bytecode files from analysis due to hardcoded __pycache__ directories and .pyc/.pyo/.pyd extensions in skip lists across multiple scanning surfaces.
- Vendor
- Tencent
- Product
- AI-Infra-Guard
- CVSS
- HIGH 7.1
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-09-02
- Original CVE updated
- 2026-09-04
- Advisory published
- 2026-09-02
- Advisory updated
- 2026-09-04
Who should care
Operators and administrators of Tencent AI-Infra-Guard, as well as security teams responsible for monitoring and protecting against potential code execution attacks, should prioritize reviewing and updating skill-scan component configurations. They should also perform inventory checks for skills with compiled Python bytecode, monitor for suspicious activity related to skill installation and execution, and implement compensating controls to detect and prevent code execution.
Technical summary
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. This allows attackers to distribute skills with benign Python source files alongside malicious compiled bytecode that executes on import, enabling code execution when operators install the skill.
Defensive priority
Operators and administrators of Tencent AI-Infra-Guard should prioritize reviewing and updating skill-scan component configurations to ensure comprehensive analysis of skills, especially those with compiled Python bytecode.
Recommended defensive actions
- Review and update skill-scan component configurations to ensure comprehensive analysis of skills
- Perform inventory checks for skills with compiled Python bytecode
- Monitor for suspicious activity related to skill installation and execution
- Implement compensating controls to detect and prevent code execution
- Exception tracking and retest procedures should be established
Evidence notes
The CVE record indicates that Tencent AI-Infra-Guard's skill-scan component excludes compiled Python bytecode files from analysis. This exclusion is due to hardcoded __pycache__ directories and .pyc/.pyo/.pyd extensions in skip lists across multiple scanning surfaces. However, the source detail is limited, and further verification is required to fully understand the vulnerability's impact and affected scope.
Sources and references
Verified primary and authoritative sources
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CVE-2026-84809 CVE Program record
Publisher, destination, and source semantics verified
URL: https://www.cve.org/CVERecord?id=CVE-2026-84809
CVE Program - Official CVE Program record with source-provided CVE metadata.
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CVE-2026-84809 NVD vulnerability detail
Publisher, destination, and source semantics verified
URL: https://nvd.nist.gov/vuln/detail/CVE-2026-84809
NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.
Supplemental references
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Source reference
Unverified legacy reference
URL: https://github.com/Tencent/AI-Infra-Guard
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Source reference
Unverified legacy reference
URL: https://github.com/Tencent/AI-Infra-Guard/blob/v4.6.0/skill-scan/skill_scan/tools/dir/dir_actions.py
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Source reference
Unverified legacy reference
URL: https://github.com/Tencent/AI-Infra-Guard/blob/v4.6.0/skill-scan/skill_scan/utils/pre_scan.py
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Source reference
Unverified legacy reference
URL: https://github.com/Tencent/AI-Infra-Guard/commit/7e0f749e3c023e5c6ab7b32fe97b3f6f2e8aeb04
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Source reference
Unverified legacy reference
URL: https://github.com/Tencent/AI-Infra-Guard/issues/531
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Source reference
Unverified legacy reference
URL: https://www.vulncheck.com/advisories/tencent-ai-infra-guard-skill-scan-analysis-bypass-via-excluded-python-bytecode
Methodology and review provenance
AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.