diff --git a/Documentation/config/credential.txt b/Documentation/config/credential.txt
index 512f31876e..9cadca7f73 100644
--- a/Documentation/config/credential.txt
+++ b/Documentation/config/credential.txt
@@ -14,6 +14,17 @@ credential.useHttpPath::
 	or https URL to be important. Defaults to false. See
 	linkgit:gitcredentials[7] for more information.
 
+credential.sanitizePrompt::
+	By default, user names and hosts that are shown as part of the
+	password prompt are not allowed to contain control characters (they
+	will be URL-encoded by default). Configure this setting to `false` to
+	override that behavior.
+
+credential.protectProtocol::
+	By default, Carriage Return characters are not allowed in the protocol
+	that is used when Git talks to a credential helper. This setting allows
+	users to override this default.
+
 credential.username::
 	If no username is set for a network authentication, use this username
 	by default. See credential.<context>.* below, and
diff --git a/credential.c b/credential.c
index f32011343f..b76a730901 100644
--- a/credential.c
+++ b/credential.c
@@ -67,6 +67,10 @@ static int credential_config_callback(const char *var, const char *value,
 	}
 	else if (!strcmp(key, "usehttppath"))
 		c->use_http_path = git_config_bool(var, value);
+	else if (!strcmp(key, "sanitizeprompt"))
+		c->sanitize_prompt = git_config_bool(var, value);
+	else if (!strcmp(key, "protectprotocol"))
+		c->protect_protocol = git_config_bool(var, value);
 
 	return 0;
 }
@@ -164,7 +168,8 @@ static void credential_format(struct credential *c, struct strbuf *out)
 		strbuf_addch(out, '@');
 	}
 	if (c->host)
-		strbuf_addstr(out, c->host);
+		strbuf_add_percentencode(out, c->host,
+					 STRBUF_ENCODE_HOST_AND_PORT);
 	if (c->path) {
 		strbuf_addch(out, '/');
 		strbuf_add_percentencode(out, c->path, 0);
@@ -178,7 +183,10 @@ static char *credential_ask_one(const char *what, struct credential *c,
 	struct strbuf prompt = STRBUF_INIT;
 	char *r;
 
-	credential_describe(c, &desc);
+	if (c->sanitize_prompt)
+		credential_format(c, &desc);
+	else
+		credential_describe(c, &desc);
 	if (desc.len)
 		strbuf_addf(&prompt, "%s for '%s': ", what, desc.buf);
 	else
@@ -256,7 +264,8 @@ int credential_read(struct credential *c, FILE *fp)
 	return 0;
 }
 
-static void credential_write_item(FILE *fp, const char *key, const char *value,
+static void credential_write_item(const struct credential *c,
+				  FILE *fp, const char *key, const char *value,
 				  int required)
 {
 	if (!value && required)
@@ -265,19 +274,23 @@ static void credential_write_item(FILE *fp, const char *key, const char *value,
 		return;
 	if (strchr(value, '\n'))
 		die("credential value for %s contains newline", key);
+	if (c->protect_protocol && strchr(value, '\r'))
+		die("credential value for %s contains carriage return\n"
+		    "If this is intended, set `credential.protectProtocol=false`",
+		    key);
 	fprintf(fp, "%s=%s\n", key, value);
 }
 
 void credential_write(const struct credential *c, FILE *fp)
 {
-	credential_write_item(fp, "protocol", c->protocol, 1);
-	credential_write_item(fp, "host", c->host, 1);
-	credential_write_item(fp, "path", c->path, 0);
-	credential_write_item(fp, "username", c->username, 0);
-	credential_write_item(fp, "password", c->password, 0);
+	credential_write_item(c, fp, "protocol", c->protocol, 1);
+	credential_write_item(c, fp, "host", c->host, 1);
+	credential_write_item(c, fp, "path", c->path, 0);
+	credential_write_item(c, fp, "username", c->username, 0);
+	credential_write_item(c, fp, "password", c->password, 0);
 	if (c->password_expiry_utc != TIME_MAX) {
 		char *s = xstrfmt("%"PRItime, c->password_expiry_utc);
-		credential_write_item(fp, "password_expiry_utc", s, 0);
+		credential_write_item(c, fp, "password_expiry_utc", s, 0);
 		free(s);
 	}
 }
diff --git a/credential.h b/credential.h
index 935b28a70f..2c0b39a925 100644
--- a/credential.h
+++ b/credential.h
@@ -119,7 +119,9 @@ struct credential {
 		 configured:1,
 		 quit:1,
 		 use_http_path:1,
-		 username_from_proto:1;
+		 username_from_proto:1,
+		 sanitize_prompt:1,
+		 protect_protocol:1;
 
 	char *username;
 	char *password;
@@ -132,6 +134,8 @@ struct credential {
 #define CREDENTIAL_INIT { \
 	.helpers = STRING_LIST_INIT_DUP, \
 	.password_expiry_utc = TIME_MAX, \
+	.sanitize_prompt = 1, \
+	.protect_protocol = 1, \
 }
 
 /* Initialize a credential structure, setting all fields to empty. */
diff --git a/strbuf.c b/strbuf.c
index c383f41a3c..756b96c561 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -492,7 +492,9 @@ void strbuf_add_percentencode(struct strbuf *dst, const char *src, int flags)
 		unsigned char ch = src[i];
 		if (ch <= 0x1F || ch >= 0x7F ||
 		    (ch == '/' && (flags & STRBUF_ENCODE_SLASH)) ||
-		    strchr(URL_UNSAFE_CHARS, ch))
+		    ((flags & STRBUF_ENCODE_HOST_AND_PORT) ?
+		     !isalnum(ch) && !strchr("-.:[]", ch) :
+		     !!strchr(URL_UNSAFE_CHARS, ch)))
 			strbuf_addf(dst, "%%%02X", (unsigned char)ch);
 		else
 			strbuf_addch(dst, ch);
diff --git a/strbuf.h b/strbuf.h
index f6dbb9681e..f9f8bb0381 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -380,6 +380,7 @@ size_t strbuf_expand_dict_cb(struct strbuf *sb,
 void strbuf_addbuf_percentquote(struct strbuf *dst, const struct strbuf *src);
 
 #define STRBUF_ENCODE_SLASH 1
+#define STRBUF_ENCODE_HOST_AND_PORT 2
 
 /**
  * Append the contents of a string to a strbuf, percent-encoding any characters
diff --git a/t/t0300-credentials.sh b/t/t0300-credentials.sh
index c66d91e82d..168ae76550 100755
--- a/t/t0300-credentials.sh
+++ b/t/t0300-credentials.sh
@@ -45,6 +45,10 @@ test_expect_success 'setup helper scripts' '
 	test -z "$pexpiry" || echo password_expiry_utc=$pexpiry
 	EOF
 
+	write_script git-credential-cntrl-in-username <<-\EOF &&
+	printf "username=\\007latrix Lestrange\\n"
+	EOF
+
 	PATH="$PWD:$PATH"
 '
 
@@ -514,6 +518,19 @@ test_expect_success 'match percent-encoded values in username' '
 	EOF
 '
 
+test_expect_success 'match percent-encoded values in hostname' '
+	test_config "credential.https://a%20b%20c/.helper" "$HELPER" &&
+	check fill <<-\EOF
+	url=https://a b c/
+	--
+	protocol=https
+	host=a b c
+	username=foo
+	password=bar
+	--
+	EOF
+'
+
 test_expect_success 'fetch with multiple path components' '
 	test_unconfig credential.helper &&
 	test_config credential.https://example.com/foo/repo.git.helper "verbatim foo bar" &&
@@ -703,6 +720,22 @@ test_expect_success 'url parser rejects embedded newlines' '
 	test_cmp expect stderr
 '
 
+test_expect_success 'url parser rejects embedded carriage returns' '
+	test_config credential.helper "!true" &&
+	test_must_fail git credential fill 2>stderr <<-\EOF &&
+	url=https://example%0d.com/
+	EOF
+	cat >expect <<-\EOF &&
+	fatal: credential value for host contains carriage return
+	If this is intended, set `credential.protectProtocol=false`
+	EOF
+	test_cmp expect stderr &&
+	GIT_ASKPASS=true \
+	git -c credential.protectProtocol=false credential fill <<-\EOF
+	url=https://example%0d.com/
+	EOF
+'
+
 test_expect_success 'host-less URLs are parsed as empty host' '
 	check fill "verbatim foo bar" <<-\EOF
 	url=cert:///path/to/cert.pem
@@ -812,4 +845,20 @@ test_expect_success 'credential config with partial URLs' '
 	test_i18ngrep "skipping credential lookup for key" stderr
 '
 
+BEL="$(printf '\007')"
+
+test_expect_success 'interactive prompt is sanitized' '
+	check fill cntrl-in-username <<-EOF
+	protocol=https
+	host=example.org
+	--
+	protocol=https
+	host=example.org
+	username=${BEL}latrix Lestrange
+	password=askpass-password
+	--
+	askpass: Password for ${SQ}https://%07latrix%20Lestrange@example.org${SQ}:
+	EOF
+'
+
 test_done
diff --git a/t/t5541-http-push-smart.sh b/t/t5541-http-push-smart.sh
index d0211cd8be..2cd2e1a059 100755
--- a/t/t5541-http-push-smart.sh
+++ b/t/t5541-http-push-smart.sh
@@ -351,7 +351,7 @@ test_expect_success 'push over smart http with auth' '
 	git push "$HTTPD_URL"/auth/smart/test_repo.git &&
 	git --git-dir="$HTTPD_DOCUMENT_ROOT_PATH/test_repo.git" \
 		log -1 --format=%s >actual &&
-	expect_askpass both user@host &&
+	expect_askpass both user%40host &&
 	test_cmp expect actual
 '
 
@@ -363,7 +363,7 @@ test_expect_success 'push to auth-only-for-push repo' '
 	git push "$HTTPD_URL"/auth-push/smart/test_repo.git &&
 	git --git-dir="$HTTPD_DOCUMENT_ROOT_PATH/test_repo.git" \
 		log -1 --format=%s >actual &&
-	expect_askpass both user@host &&
+	expect_askpass both user%40host &&
 	test_cmp expect actual
 '
 
@@ -393,7 +393,7 @@ test_expect_success 'push into half-auth-complete requires password' '
 	git push "$HTTPD_URL/half-auth-complete/smart/half-auth.git" &&
 	git --git-dir="$HTTPD_DOCUMENT_ROOT_PATH/half-auth.git" \
 		log -1 --format=%s >actual &&
-	expect_askpass both user@host &&
+	expect_askpass both user%40host &&
 	test_cmp expect actual
 '
 
diff --git a/t/t5550-http-fetch-dumb.sh b/t/t5550-http-fetch-dumb.sh
index 8f182a3cbf..5d0e394609 100755
--- a/t/t5550-http-fetch-dumb.sh
+++ b/t/t5550-http-fetch-dumb.sh
@@ -90,13 +90,13 @@ test_expect_success 'http auth can use user/pass in URL' '
 test_expect_success 'http auth can use just user in URL' '
 	set_askpass wrong pass@host &&
 	git clone "$HTTPD_URL_USER/auth/dumb/repo.git" clone-auth-pass &&
-	expect_askpass pass user@host
+	expect_askpass pass user%40host
 '
 
 test_expect_success 'http auth can request both user and pass' '
 	set_askpass user@host pass@host &&
 	git clone "$HTTPD_URL/auth/dumb/repo.git" clone-auth-both &&
-	expect_askpass both user@host
+	expect_askpass both user%40host
 '
 
 test_expect_success 'http auth respects credential helper config' '
@@ -114,14 +114,14 @@ test_expect_success 'http auth can get username from config' '
 	test_config_global "credential.$HTTPD_URL.username" user@host &&
 	set_askpass wrong pass@host &&
 	git clone "$HTTPD_URL/auth/dumb/repo.git" clone-auth-user &&
-	expect_askpass pass user@host
+	expect_askpass pass user%40host
 '
 
 test_expect_success 'configured username does not override URL' '
 	test_config_global "credential.$HTTPD_URL.username" wrong &&
 	set_askpass wrong pass@host &&
 	git clone "$HTTPD_URL_USER/auth/dumb/repo.git" clone-auth-user2 &&
-	expect_askpass pass user@host
+	expect_askpass pass user%40host
 '
 
 test_expect_success 'set up repo with http submodules' '
@@ -142,7 +142,7 @@ test_expect_success 'cmdline credential config passes to submodule via clone' '
 	set_askpass wrong pass@host &&
 	git -c "credential.$HTTPD_URL.username=user@host" \
 		clone --recursive super super-clone &&
-	expect_askpass pass user@host
+	expect_askpass pass user%40host
 '
 
 test_expect_success 'cmdline credential config passes submodule via fetch' '
@@ -153,7 +153,7 @@ test_expect_success 'cmdline credential config passes submodule via fetch' '
 	git -C super-clone \
 	    -c "credential.$HTTPD_URL.username=user@host" \
 	    fetch --recurse-submodules &&
-	expect_askpass pass user@host
+	expect_askpass pass user%40host
 '
 
 test_expect_success 'cmdline credential config passes submodule update' '
@@ -170,7 +170,7 @@ test_expect_success 'cmdline credential config passes submodule update' '
 	git -C super-clone \
 	    -c "credential.$HTTPD_URL.username=user@host" \
 	    submodule update &&
-	expect_askpass pass user@host
+	expect_askpass pass user%40host
 '
 
 test_expect_success 'fetch changes via http' '
diff --git a/t/t5551-http-fetch-smart.sh b/t/t5551-http-fetch-smart.sh
index 0908534f25..8a27768dfb 100755
--- a/t/t5551-http-fetch-smart.sh
+++ b/t/t5551-http-fetch-smart.sh
@@ -181,7 +181,7 @@ test_expect_success 'clone from password-protected repository' '
 	echo two >expect &&
 	set_askpass user@host pass@host &&
 	git clone --bare "$HTTPD_URL/auth/smart/repo.git" smart-auth &&
-	expect_askpass both user@host &&
+	expect_askpass both user%40host &&
 	git --git-dir=smart-auth log -1 --format=%s >actual &&
 	test_cmp expect actual
 '
@@ -199,7 +199,7 @@ test_expect_success 'clone from auth-only-for-objects repository' '
 	echo two >expect &&
 	set_askpass user@host pass@host &&
 	git clone --bare "$HTTPD_URL/auth-fetch/smart/repo.git" half-auth &&
-	expect_askpass both user@host &&
+	expect_askpass both user%40host &&
 	git --git-dir=half-auth log -1 --format=%s >actual &&
 	test_cmp expect actual
 '
@@ -224,14 +224,14 @@ test_expect_success 'redirects send auth to new location' '
 	set_askpass user@host pass@host &&
 	git -c credential.useHttpPath=true \
 	  clone $HTTPD_URL/smart-redir-auth/repo.git repo-redir-auth &&
-	expect_askpass both user@host auth/smart/repo.git
+	expect_askpass both user%40host auth/smart/repo.git
 '
 
 test_expect_success 'GIT_TRACE_CURL redacts auth details' '
 	rm -rf redact-auth trace &&
 	set_askpass user@host pass@host &&
 	GIT_TRACE_CURL="$(pwd)/trace" git clone --bare "$HTTPD_URL/auth/smart/repo.git" redact-auth &&
-	expect_askpass both user@host &&
+	expect_askpass both user%40host &&
 
 	# Ensure that there is no "Basic" followed by a base64 string, but that
 	# the auth details are redacted
@@ -243,7 +243,7 @@ test_expect_success 'GIT_CURL_VERBOSE redacts auth details' '
 	rm -rf redact-auth trace &&
 	set_askpass user@host pass@host &&
 	GIT_CURL_VERBOSE=1 git clone --bare "$HTTPD_URL/auth/smart/repo.git" redact-auth 2>trace &&
-	expect_askpass both user@host &&
+	expect_askpass both user%40host &&
 
 	# Ensure that there is no "Basic" followed by a base64 string, but that
 	# the auth details are redacted
@@ -256,7 +256,7 @@ test_expect_success 'GIT_TRACE_CURL does not redact auth details if GIT_TRACE_RE
 	set_askpass user@host pass@host &&
 	GIT_TRACE_REDACT=0 GIT_TRACE_CURL="$(pwd)/trace" \
 		git clone --bare "$HTTPD_URL/auth/smart/repo.git" redact-auth &&
-	expect_askpass both user@host &&
+	expect_askpass both user%40host &&
 
 	grep -i "Authorization: Basic [0-9a-zA-Z+/]" trace
 '
@@ -568,7 +568,7 @@ test_expect_success 'http auth remembers successful credentials' '
 	# the first request prompts the user...
 	set_askpass user@host pass@host &&
 	git ls-remote "$HTTPD_URL/auth/smart/repo.git" >/dev/null &&
-	expect_askpass both user@host &&
+	expect_askpass both user%40host &&
 
 	# ...and the second one uses the stored value rather than
 	# prompting the user.
@@ -599,7 +599,7 @@ test_expect_success 'http auth forgets bogus credentials' '
 	# us to prompt the user again.
 	set_askpass user@host pass@host &&
 	git ls-remote "$HTTPD_URL/auth/smart/repo.git" >/dev/null &&
-	expect_askpass both user@host
+	expect_askpass both user%40host
 '
 
 test_expect_success 'client falls back from v2 to v0 to match server' '