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CRLF injection in default email rule

High
andrei-laravel published GHSA-5vg9-5847-vvmq Jun 1, 2026

Package

composer laravel/framework (Composer)

Affected versions

<= 13.9.0
< 12.60.0

Patched versions

>= 13.10.0
>= 12.60.0

Description

Summary

A CRLF injection vulnerability in Laravel's email validation, in combination with how Symfony Mailer and Symfony Mime handle certain character sequences, may allow an unauthenticated attacker to interfere with outbound email processing in applications that send mail to user-supplied addresses.

Description

Laravel applications that send email to addresses provided by users — for example during authentication flows or contact forms — may be vulnerable to manipulation of outbound mail content if the address is not adequately sanitized before it reaches the mail transport layer.
An attacker who can supply an email address to such a flow may, under certain conditions, be able to influence the content of emails sent by the application, cause those emails to be delivered to unintended recipients, or cause the application's mail server to send unintended messages.

Impact

Affected applications may be exposed to unauthorized access and mail relay abuse. The severity depends on what the application sends by email and how its mail infrastructure is configured.

Remediation

Upgrade to version 12.60.0 or later, or 13.10.0 or later.

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
Low

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:L

CVE ID

CVE-2026-48019

Weaknesses

Improper Neutralization of CRLF Sequences ('CRLF Injection')

The product uses CRLF (carriage return line feeds) as a special element, e.g. to separate lines or records, but it does not neutralize or incorrectly neutralizes CRLF sequences from inputs. Learn more on MITRE.

Credits