{"record":{"id":"1233efbb0c46a241","repo":"Seldaek/monolog","slug":"headers-can-not-contain-newline-characters-for-sec","errorCode":null,"errorMessage":"Headers can not contain newline characters for security reasons","messagePattern":"Headers can not contain newline characters for security reasons","errorType":"exception","errorClass":"InvalidArgumentException","httpStatus":null,"severity":"error","filePath":"src/Monolog/Handler/NativeMailerHandler.php","lineNumber":88,"sourceCode":"    {\n        parent::__construct($level, $bubble);\n        $this->to = (array) $to;\n        $this->subject = $subject;\n        $this->addHeader(sprintf('From: %s', $from));\n        $this->maxColumnWidth = $maxColumnWidth;\n    }\n\n    /**\n     * Add headers to the message\n     *\n     * @param  string|string[] $headers Custom added headers\n     * @return $this\n     */\n    public function addHeader($headers): self\n    {\n        foreach ((array) $headers as $header) {\n            if (strpos($header, \"\\n\") !== false || strpos($header, \"\\r\") !== false) {\n                throw new \\InvalidArgumentException('Headers can not contain newline characters for security reasons');\n            }\n            $this->headers[] = $header;\n        }\n\n        return $this;\n    }\n\n    /**\n     * Add parameters to the message\n     *\n     * @param  string|string[] $parameters Custom added parameters\n     * @return $this\n     */\n    public function addParameter($parameters): self\n    {\n        $this->parameters = array_merge($this->parameters, (array) $parameters);\n\n        return $this;","sourceCodeStart":70,"sourceCodeEnd":106,"githubUrl":"https://github.com/Seldaek/monolog/blob/57eb1028342134e701e77c617565d51b6e5a2a53/src/Monolog/Handler/NativeMailerHandler.php#L70-L106","documentation":"Error \"Headers can not contain newline characters for security reasons\" thrown in Seldaek/monolog.","triggerScenarios":"Thrown at src/Monolog/Handler/NativeMailerHandler.php:88 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":[],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"57eb1028342134e701e77c617565d51b6e5a2a53","analyzedAt":"2026-08-17T02:36:30.259Z","schemaVersion":2},"datasetVersion":"2026-08-17T04:17:16.089Z"}