CVE-2026-31862

EUVD-2026-11265 · Published Mar 11, 2026

@siteboon/claude-code-ui is Vulnerable to Command Injection via Multiple Parameters

Summary

Multiple Git-related API endpoints use execAsync() with string interpolation of user-controlled parameters (file, branch, message, commit), allowing authenticated attackers to execute arbitrary OS commands.

Details

The claudecodeui application provides Git integration through various API endpoints. These endpoints accept user-controlled parameters such as file paths, branch names, commit messages, and commit hashes, which are directly interpolated into shell command strings passed to execAsync().

The application attempts to escape double quotes in some parameters, but this protection is trivially bypassable using other shell metacharacters such as:

Command substitution: $(command) or `command`
Command chaining: ;, &&, ||
Newlines and other control characters

Affected Endpoints

GET /api/git/diff - file parameter
GET /api/git/status - file parameter
POST /api/git/commit - files array and message parameter
POST /api/git/checkout - branch parameter
POST /api/git/create-branch - branch parameter
GET /api/git/commits - commit hash parameter
GET /api/git/commit-diff - commit parameter

Vulnerable Code

File: server/routes/git.js

// Line 205 - git status with file parameter
const { stdout: statusOutput } = await execAsync(
  `git status --porcelain "${file}"`,  // INJECTION via file
  { cwd: projectPath }
);

// Lines 375-379 - git commit with files array and message
for (const file of files) {
  await execAsync(`git add "${file}"`, { cwd: projectPath });  // INJECTION via files[]
}
const { stdout } = await execAsync(
  `git commit -m "${message.replace(/"/g, '\\"')}"`,  // INJECTION via message (bypass with $())
  { cwd: projectPath }
);

// Lines 541-543 - git show with commit parameter (no quotes!)
const { stdout } = await execAsync(
  `git show ${commit}`,  // INJECTION via commit
  { cwd: projectPath }
);

Impact

Remote Code Execution as the Node.js process user
Full server compromise
Data exfiltration
Supply chain attacks - modify committed code to inject malware

Fix

Commit: siteboon/claudecodeui@55567f4

Root cause remediation

All vulnerable execAsync() calls have been replaced with the existing spawnAsync() helper (which uses child_process.spawn with shell: false). Arguments are passed as an array directly to the OS — shell metacharacters in user input are inert.

Endpoints patched in server/routes/git.js:

GET /api/git/diff — file (4 calls)
GET /api/git/file-with-diff — file (3 calls)
POST /api/git/commit — files[], message
POST /api/git/checkout — branch
POST /api/git/create-branch — branch
GET /api/git/commits — commit.hash
GET /api/git/commit-diff — commit
POST /api/git/generate-commit-message — file
POST /api/git/discard — file (3 calls)
POST /api/git/delete-untracked — file
POST /api/git/publish — branch

A strict allowlist regex (/^[0-9a-f]{4,64}$/i) was also added to validate the commit parameter in /api/git/commit-diff before it reaches the git process.

Before / After

// BEFORE — shell interprets the string, injection possible
const { stdout } = await execAsync(`git show ${commit}`, { cwd: projectPath });

// AFTER — no shell, args passed directly to the process
const { stdout } = await spawnAsync('git', ['show', commit], { cwd: projectPath });

Technologies

Cloudcli Cloud CliSiteboon Claudecodeui

Weaknesses

CWE-78CWE-77

CVSS scores

v3.19.1CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

MITRE ATT&CK

Inferred

Where this vulnerability fits in an attack

ReconImpact

Initial Access

T1190Exploit Public-Facing Application

References

Potentially impacted assets

See if this affects your attack surface

Latest trending attack

Criticalyesterday

Google Brotli decoder - Remote Code Execution via compressed requests (Exploitation Check)

This control is the second step of the Patrowl response to CVE-2026-111497 (Node2Shell). It complements the first control of 22 October 2026, which focused on the Node.js runtime, and does not replace it. Why a second control CVE-2026-111497 is an out-of-bounds write in the Google Brotli decoder, the library that decompresses Brotli ("br") data. It was first published as a Node.js vulnerability, because Node.js bundles this decoder. Later publications showed that the flaw is in the library itself. Every product that embeds an affected version of the decoder is concerned, whatever its language or vendor. A public proof of concept demonstrates code execution. Any server that decompresses request bodies sent with "Content-Encoding: br" exposes the decoder to unauthenticated attackers. Known cases include Express 5 and NestJS 11 on Node.js, Koa and Fastify setups, Bun, Envoy and Istio with request decompression enabled, and any application or reverse proxy that decodes Brotli request bodies with an affected library. The flaw also works in the other direction. A malicious server can compromise an unpatched client that decodes a Brotli response, for example Node.js fetch(), Python clients (requests, httpx, aiohttp, Scrapy) with the Brotli or brotlicffi package, or libcurl builds with Brotli support. What this control checks Patrowl sends small, valid Brotli-compressed requests to each asset and observes whether the server decodes them. The check does not depend on the technology: it detects the behaviour, whatever the stack behind it. These requests are what any legitimate client could send. They never reach the vulnerable code path and cannot affect the availability of the service. How to read the result Potentially impacted means the asset decodes Brotli request bodies: the attack surface is exposed. It does not confirm that the asset is vulnerable. The version of the Brotli decoder in use is not visible from the outside. This check covers applications that parse request bodies on their root path. A Not impacted result does not rule out exposure on other routes, nor on the client side. Checking the versions on the servers remains the only exhaustive verification. Affected and fixed versions Google Brotli 1.0.3 to 1.2.0 are affected, fixed in 1.0.10, 1.1.1 and 1.2.1. Fixed releases of the main products embedding it: Node.js 22.23.4, 24.22.1 and 26.12.1 (end-of-life lines 20.x and older and 25.x receive no fix), Bun 1.4.4, Envoy 1.37.8, 1.38.6, 1.39.3 and 1.40.0, Istio 1.29.9, 1.30.6 and 1.31.2, Python Brotli 1.2.1 and brotlicffi 1.2.1.0. Products that link against the system library depend on the Brotli package of the Linux distribution. Recommendations Update every component that embeds the Brotli decoder (only real fix). Start with the assets flagged by this control. Restart the processes after the update. Rebuild containers, single-executable applications and appliances that bundle an affected runtime or library. Reduce the exposure until the update is deployed. Reject requests with "Content-Encoding: br" at the reverse proxy, load balancer or WAF, case-insensitively and including lists such as "gzip, br". On Envoy and Istio, disable request decompression for Brotli. Review outbound calls. List the features that fetch content from servers you do not control, and patch the services that host them first.