diff --git a/lib/Service/DomainService.php b/lib/Service/DomainService.php
index eb62841dfe346e78d3dc9514749cf2976bf68136..ad7b4804f660557b540333ad4dfd49fc23557e58 100644
--- a/lib/Service/DomainService.php
+++ b/lib/Service/DomainService.php
@@ -72,8 +72,17 @@ class DomainService {
 	 * Add a custom disposable domain to the list.
 	 */
 	public function addCustomDisposableDomain(string $domain, IL10N $l, array $relatedDomains = []): void {
+		// Sanitize the domain and related domains to remove control characters
+		$cleanDomain = preg_replace('/[\x00-\x1F\x7F]/', '', $domain);
+		$cleanRelatedDomains = array_map(fn ($relatedDomain) => preg_replace('/[\x00-\x1F\x7F]/', '', $relatedDomain), $relatedDomains);
+	
+		// Get existing domains from the file
 		$domains = $this->getDomainsFromFile(self::DISPOSABLE_DOMAINS_FILE, $l);
-		$newDomains = array_unique(array_merge($domains, [$domain], $relatedDomains));
+	
+		// Merge, deduplicate, and sanitize
+		$newDomains = array_unique(array_merge($domains, [$cleanDomain], $cleanRelatedDomains));
+	
+		// Save the updated list to the file
 		$this->saveDomainsToFile(self::DISPOSABLE_DOMAINS_FILE, $newDomains);
 	}