CVE-2026-77521Public exploitNetwork attack vectorHinoki check available

Host command execution via ungated shell tool

Published Sep 21, 2026 · Updated Sep 21, 2026

Command injection in KubeOperator MaxKB before 2.10.5-lts allows remote attackers to execute host commands through untrusted assistant input. SandboxShellBackend exposes an execute tool to the model and omits execute from the human-approval gate; its string-based root wrapper also evaluates shell metacharacters outside gosu. Exploitation requires a tool-, MCP-, skill-, or sub-application-enabled assistant and attacker-controlled chat or ingested content, granting the application user's host or container privileges.

CVSS severity10.0
Critical
EPSS probability1.05%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Command injection in KubeOperator MaxKB before 2.10.5-lts allows remote attackers to execute host commands through untrusted assistant input. SandboxShellBackend exposes an execute tool to the model and omits execute from the human-approval gate; its string-based root wrapper also evaluates shell metacharacters outside gosu. Exploitation requires a tool-, MCP-, skill-, or sub-application-enabled assistant and attacker-controlled chat or ingested content, granting the application user's host or container privileges.

The record

CVE
CVE-2026-77521
Published
Sep 21, 2026
Updated
Sep 21, 2026
Vendor
KubeOperator
Product
MaxKB
Classifications
CWE-78, CWE-749, CWE-250, T1059
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 21, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 21, 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.

  1. Affected versionversion=< 2.10.5-lts

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

KubeOperator · MaxKBversion=< 2.10.5-lts

Published CVSS scores

10.0GitHub Security AdvisoryCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

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.

Activity data is delayed. The latest report is Sep 28, 2026.

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

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
CWE-749Exposed Dangerous Method or Function
CWE-250Execution with Unnecessary Privileges
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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