CVE-2026-77521: Command Injection (CVSS 10)

Description

MaxKB is an open-source AI assistant for enterprise. Prior to version 2.10.5-lts, assistants with a tool, MCP tool, skill, or sub-application use SandboxShellBackend, which exposes an execute shell tool without excluding it and omits execute from interrupt_on, so human approval is not required. Untrusted chat or ingested content can therefore cause command execution; source deployments with MAXKB_SANDBOX disabled run commands directly as the application user, while the official root container's string-based gosu wrapper allowed shell metacharacters to execute outside the intended sandbox. This issue is fixed in version 2.10.5-lts.

Is your site exposed to CVE-2026-77521?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

10.0

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0105

Probability of exploitation

0.64%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-78 OS Command Injection

CWE-250 CWE-250

CWE-749 CWE-749

References

Other References

https://github.com/1Panel-dev/MaxKB/commit/594f50f2ea80a502d1c955371ba0438b277c30ea https://github.com/1Panel-dev/MaxKB/releases/tag/v2.10.5-lts https://github.com/1Panel-dev/MaxKB/security/advisories/GHSA-f36j-f34j-h3rx https://github.com/1Panel-dev/MaxKB/security/advisories/GHSA-f36j-f34j-h3rx

Frequently Asked Questions

What is CVE-2026-77521? +

MaxKB is an open-source AI assistant for enterprise. Prior to version 2.10.5-lts, assistants with a tool, MCP tool, skill, or sub-application use SandboxShellBackend, which exposes an execute shell tool without excluding it and omits execute from interrupt_on, so human approval is not required. Untrusted chat or ingested content can therefore cause command execution; source deployments with MAXKB_SANDBOX disabled run commands directly as the application user, while the official root container's string-based gosu wrapper allowed shell metacharacters to execute outside the intended sandbox. This issue is fixed in version 2.10.5-lts. It has a CVSS v3.1 base score of 10.0 (CRITICAL).

How severe is CVE-2026-77521? +

CVE-2026-77521 has a CVSS v3.1 score of 10.0 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0105, placing it in the 1th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-77521? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2024-54012

Penetration Testing engineers at Amazon discovered a vulnerability where the camera system failed to properly validate input, allowing specially crafted …

CVE-2026-8652

An OS Command Injection vulnerability exists in Aterm. If a malicious third person gains administrator access to the product’s web …

CVE-2026-34007

An OS command injection vulnerability has been reported to affect Notes Station 3. If exploited, the vulnerability could allow remote …

CVE-2025-13605

3onedata modbus gateway device model GW1101-1D(RS-485)-TB-P (hardware version V2.2.0) allows authenticated users to execute arbitrary shell commands in the context …

CVE-2026-41925

WDR201A WiFi Extender (HW V2.1, FW LFMZX28040922V1.02) contains an OS command injection vulnerability in the adm.cgi binary's reboot_time function that …

CVE-2026-41924

WDR201A WiFi Extender (HW V2.1, FW LFMZX28040922V1.02) contains an OS command injection vulnerability in the makeRequest.cgi binary that allows unauthenticated …

CVE-2026-77521