Malicious skill acceptance via manifest-only directory scan
Published Sep 2, 2026 · Updated Sep 2, 2026
Protection mechanism failure in Claude World Claude Skill Antivirus 2.1.3 and earlier allows attackers to conceal malicious skill code. The fetchLocal directory path in src/utils/downloader.js reads only SKILL.md and supplies a single-file SkillContent object to all nine engines. A recipient must scan and then install or use the crafted skill; omitted scripts can execute without having influenced the SAFE verdict.
Summary
What happened
Protection mechanism failure in Claude World Claude Skill Antivirus 2.1.3 and earlier allows attackers to conceal malicious skill code. The fetchLocal directory path in src/utils/downloader.js reads only SKILL.md and supplies a single-file SkillContent object to all nine engines. A recipient must scan and then install or use the crafted skill; omitted scripts can execute without having influenced the SAFE verdict.
The record
- CVE
- CVE-2026-84810
- Published
- Sep 2, 2026
- Updated
- Sep 2, 2026
- Vendor
- Claude World
- Product
- Claude Skill Antivirus
- Classifications
- CWE-693, T1204.002
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 2, 2026CVE publishedPublication date reported by the CVE source.
- Sep 2, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <=2.1.3
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- skills-scanner-bypass proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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