CVE-2026-79623Public exploitNetwork attack vector

Worker command execution via project hook injection

Published Aug 25, 2026 · Updated Aug 27, 2026

OS command injection in FishCodeTech Muteki 0.2.0 through 0.2.5 allows remote authenticated users to execute commands via a crafted archive. A challenge archive can place .claude/settings.json in the local worker's current directory, where a later headless Claude Code launch trusts it and runs its SessionStart hook. Exploitation requires local worker mode, worker isolation disabled, archive extraction, and a fresh Claude Code session; commands run with the worker user's privileges.

CVSS severityUnavailable
Unscored
EPSS probability1.42%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OS command injection in FishCodeTech Muteki 0.2.0 through 0.2.5 allows remote authenticated users to execute commands via a crafted archive. A challenge archive can place .claude/settings.json in the local worker's current directory, where a later headless Claude Code launch trusts it and runs its SessionStart hook. Exploitation requires local worker mode, worker isolation disabled, archive extraction, and a fresh Claude Code session; commands run with the worker user's privileges.

The record

CVE
CVE-2026-79623
Published
Aug 25, 2026
Updated
Aug 27, 2026
Vendor
FishCodeTech
Product
Muteki
Classifications
CWE-78, CWE-77, T1059
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0.2.0
  2. Affected versionversion=0.2.1
  3. Affected versionversion=0.2.2
  4. Affected versionversion=0.2.3
  5. Affected versionversion=0.2.4
  6. Affected versionversion=0.2.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

FishCodeTech · Mutekiversion=0.2.0; version=0.2.1; version=0.2.2; version=0.2.3; version=0.2.4; version=0.2.5

Published CVSS scores

5.3VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
6.5VulDBAV:N/AC:L/Au:S/C:P/I:P/A:P/E:POC/RL:ND/RC:UR
6.3VulDBCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L/E:P/RL:X/RC:R
6.3VulDBCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L/E:P/RL:X/RC:R

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
CWE-77Improper Neutralization of Special Elements used in a Command ('Command Injection')
T1059Command and Scripting Interpreter

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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