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How CVE-2026-48505 Works
Filament is a collection of full-stack components for accelerated Laravel development. Versions 4.0.0 through 4.11.5 and 5.0.0 through 5.6.5 contain a flaw in the handling of recovery codes for app-based multi-factor authentication (MFA). The vulnerability stems from improper handling of recovery code validation where the system fails to properly track or invalidate recovery codes upon first use. This design oversight allows concurrent submission of the same recovery code across multiple authentication attempts, effectively enabling an attacker to consume a single recovery code multiple times.
The core issue is a race condition (CWE-362). When a user submits a recovery code, the system validates it and, if correct, authenticates the session. However, due to improper synchronization, if multiple authentication requests containing the same recovery code are submitted at the same time, they can all pass validation before any single request has a chance to mark the code as used. This allows the same recovery code to be burned multiple times, granting multiple authenticated sessions from a single code.
This issue does not affect email-based MFA and only applies when recovery codes are enabled. Under normal circumstances, recovery codes should provide only one authenticated session per code consumption. However, this flaw allows for multiple simultaneous sessions to be established with each code usage. If an attacker gains access to both the user’s password and their recovery codes, they get two authenticated sessions per recovery code burned instead of one, or more if they batch the parallel submissions wider, materially extending the attacker’s window of access compared to what the single-use guarantee implies.
The vulnerability maps to CWE-841 (Improper Enforcement of Behavioral Workflow) and aligns with ATT&CK technique T1078 (Valid Accounts). It represents a critical failure in session management and credential validation within the authentication flow. The vulnerability is fixed in versions 4.11.5 and 5.6.5.
DailyCVE Form
Platform: Filament (Laravel)
Version: 4.0.0-4.11.5, 5.0.0-5.6.5
Vulnerability: Recovery Code Race Condition
Severity: High (CVSS 7.4)
date: 2026-06-22
Prediction: 2026-06-25 (Patched)
What Undercode Say
Check installed Filament version composer show filament/filament Check if vulnerable (returns version) php artisan filament:about Verify recovery code table structure php artisan db:table recovery_codes --schema Simulate concurrent recovery code submission (conceptual) curl -X POST https://example.com/mfa/verify \ -d "recovery_code=XXXX-XXXX-XXXX" & curl -X POST https://example.com/mfa/verify \ -d "recovery_code=XXXX-XXXX-XXXX" & wait Monitor active sessions before and after exploit php artisan tinker --execute="dd(session()->all())"
Exploit
An attacker with a valid recovery code can exploit this vulnerability by sending multiple concurrent authentication requests using the same code. Since the system does not properly synchronize the validation and invalidation of the code, multiple requests can pass validation before the code is marked as used. This grants the attacker multiple authenticated sessions from a single recovery code. The attack can be automated using tools like `curl` or `Burp Suite` to send parallel requests, effectively multiplying the attacker’s access window.
Protection
- Upgrade Immediately: Update to Filament version 4.11.5 or 5.6.5, which contain the fix.
- Implement Atomic Operations: Ensure recovery code validation and invalidation are performed as a single atomic database transaction to prevent race conditions.
- Use Database Locks: Apply row-level locking on the recovery code record during validation to block concurrent access.
- Rate Limiting: Implement strict rate limiting on MFA endpoints to reduce the feasibility of concurrent attacks.
- Audit Logs: Monitor for multiple successful MFA verifications using the same recovery code within a short time window.
Impact
- Session Multiplication: A single recovery code can generate two or more authenticated sessions instead of one.
- Extended Access Window: Attackers can maintain unauthorized access for longer periods.
- Credential Reuse: Compromised recovery codes have a greater impact than intended.
- Bypass of Single-Use Guarantee: The fundamental security principle of recovery codes is broken.
- Account Takeover Risk: Combined with compromised passwords, this vulnerability significantly increases the risk of full account compromise.
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Sources:
Reported By: github.com
Extra Source Hub:
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