diff --git a/src/Model/User.php b/src/Model/User.php
index 35ea835b30..75b913250c 100644
--- a/src/Model/User.php
+++ b/src/Model/User.php
@@ -757,7 +757,7 @@ class User
 	}
 
 	/**
-	 * Allowed characters are a-z, A-Z, 0-9 and special characters except white spaces, accentuated letters and colon (:).
+	 * Allowed characters are a-z, A-Z, 0-9 and special characters except white spaces and accentuated letters.
 	 *
 	 * Password length is limited to 72 characters if the current default password hashing algorithm is Blowfish.
 	 * From the manual: "Using the PASSWORD_BCRYPT as the algorithm, will result in the password parameter being
@@ -770,7 +770,7 @@ class User
 	 */
 	public static function getPasswordRegExp(string $delimiter = null): string
 	{
-		$allowed_characters = '!"#$%&\'()*+,-./;<=>?@[\]^_`{|}~';
+		$allowed_characters = ':!"#$%&\'()*+,-./;<=>?@[\]^_`{|}~';
 
 		if ($delimiter) {
 			$allowed_characters = preg_quote($allowed_characters, $delimiter);
@@ -804,7 +804,7 @@ class User
 		}
 
 		if (!preg_match('/' . self::getPasswordRegExp('/') . '/', $password)) {
-			throw new Exception(DI::l10n()->t('The password can\'t contain accentuated letters, white spaces or colons (:)'));
+			throw new Exception(DI::l10n()->t("The password can't contain white spaces nor accentuated letters"));
 		}
 
 		return self::updatePasswordHashed($uid, self::hashPassword($password));
diff --git a/src/Module/OAuth/Token.php b/src/Module/OAuth/Token.php
index 7481bf75f5..6f68215cc6 100644
--- a/src/Module/OAuth/Token.php
+++ b/src/Module/OAuth/Token.php
@@ -61,7 +61,10 @@ class Token extends BaseApi
 		}
 
 		if (empty($request['client_id']) && substr($authorization, 0, 6) == 'Basic ') {
-			$datapair = explode(':', base64_decode(trim(substr($authorization, 6))));
+			// Per RFC2617, usernames can't contain a colon but password can,
+			// so we cut on the first colon to obtain the username and the password
+			// @see https://www.rfc-editor.org/rfc/rfc2617#section-2
+			$datapair = explode(':', base64_decode(trim(substr($authorization, 6))), 2);
 			if (count($datapair) == 2) {
 				$request['client_id']     = $datapair[0];
 				$request['client_secret'] = $datapair[1];
diff --git a/src/Module/Security/PasswordTooLong.php b/src/Module/Security/PasswordTooLong.php
index 1934556b3f..53fafea41e 100644
--- a/src/Module/Security/PasswordTooLong.php
+++ b/src/Module/Security/PasswordTooLong.php
@@ -98,7 +98,7 @@ class PasswordTooLong extends \Friendica\BaseModule
 			'$return_url'          => $request['return_url'] ?? '',
 
 			'$password_current' => ['password_current', $this->l10n->t('Current Password:'), '', $this->l10n->t('Your current password to confirm the changes'), 'required', 'autocomplete="off"'],
-			'$password'         => ['password', $this->l10n->t('New Password:'), '', $this->l10n->t('Allowed characters are a-z, A-Z, 0-9 and special characters except white spaces, accentuated letters and colon (:).') . ' ' . $this->l10n->t('Password length is limited to 72 characters.'), 'required', 'autocomplete="off"', User::getPasswordRegExp()],
+			'$password'         => ['password', $this->l10n->t('New Password:'), '', $this->l10n->t('Allowed characters are a-z, A-Z, 0-9 and special characters except white spaces and accentuated letters.') . ' ' . $this->l10n->t('Password length is limited to 72 characters.'), 'required', 'autocomplete="off"', User::getPasswordRegExp()],
 			'$password_confirm' => ['password_confirm', $this->l10n->t('Confirm:'), '', '', 'required', 'autocomplete="off"'],
 		]);
 
diff --git a/src/Module/Settings/Account.php b/src/Module/Settings/Account.php
index df8d41519c..f8f65e7206 100644
--- a/src/Module/Settings/Account.php
+++ b/src/Module/Settings/Account.php
@@ -549,7 +549,7 @@ class Account extends BaseSettings
 
 		$notify_type = DI::pConfig()->get(DI::userSession()->getLocalUserId(), 'system', 'notify_type');
 
-		$passwordRules = DI::l10n()->t('Allowed characters are a-z, A-Z, 0-9 and special characters except white spaces, accentuated letters and colon (:).')
+		$passwordRules = DI::l10n()->t('Allowed characters are a-z, A-Z, 0-9 and special characters except white spaces and accentuated letters.')
 			. (PASSWORD_DEFAULT === PASSWORD_BCRYPT ? ' ' . DI::l10n()->t('Password length is limited to 72 characters.') : '');
 
 		$tpl = Renderer::getMarkupTemplate('settings/account.tpl');