diff --git a/Libraries/LibHTTP/Cookie/ParsedCookie.cpp b/Libraries/LibHTTP/Cookie/ParsedCookie.cpp
index c4f0a39dcb..74c1f89575 100644
--- a/Libraries/LibHTTP/Cookie/ParsedCookie.cpp
+++ b/Libraries/LibHTTP/Cookie/ParsedCookie.cpp
@@ -103,6 +103,44 @@ Optional<ParsedCookie> parse_cookie(URL::URL const& url, StringView cookie_strin
 
 ErrorOr<ParsedCookie> parse_cookie(Cookie const& cookie)
 {
+    if (cookie.name.is_empty() && cookie.value.is_empty())
+        return Error::from_string_literal("Cookie name and value cannot both be empty");
+
+    if (cookie_contains_invalid_control_character(cookie.name))
+        return Error::from_string_literal("Cookie name contains an invalid control character");
+    if (cookie_contains_invalid_control_character(cookie.value))
+        return Error::from_string_literal("Cookie value contains an invalid control character");
+
+    if (cookie.name.byte_count() + cookie.value.byte_count() > 4096)
+        return Error::from_string_literal("Cookie name and value exceed the maximum size");
+
+    if (!cookie.path.bytes_as_string_view().starts_with("/"sv))
+        return Error::from_string_literal("Cookie path must start with /");
+    if (cookie.path.byte_count() > 1024)
+        return Error::from_string_literal("Cookie path exceeds the maximum size");
+
+    if (cookie.same_site == SameSite::None && !cookie.secure)
+        return Error::from_string_literal("SameSite=None cookies must be secure");
+
+    if (cookie.name.starts_with_bytes("__Secure-"sv, CaseSensitivity::CaseInsensitive) && !cookie.secure)
+        return Error::from_string_literal("__Secure- cookies must be secure");
+
+    if (cookie.name.starts_with_bytes("__Host-"sv, CaseSensitivity::CaseInsensitive)) {
+        if (!cookie.secure)
+            return Error::from_string_literal("__Host- cookies must be secure");
+        if (!cookie.host_only)
+            return Error::from_string_literal("__Host- cookies must be host-only");
+        if (cookie.path != "/"sv)
+            return Error::from_string_literal("__Host- cookies must use path /");
+    }
+
+    if (cookie.name.is_empty()) {
+        if (cookie.value.starts_with_bytes("__Secure-"sv, CaseSensitivity::CaseInsensitive))
+            return Error::from_string_literal("__Secure- cookies must have a name");
+        if (cookie.value.starts_with_bytes("__Host-"sv, CaseSensitivity::CaseInsensitive))
+            return Error::from_string_literal("__Host- cookies must have a name");
+    }
+
     ParsedCookie parsed_cookie;
     parsed_cookie.name = cookie.name;
     parsed_cookie.value = cookie.value;
@@ -111,6 +149,9 @@ ErrorOr<ParsedCookie> parse_cookie(Cookie const& cookie)
     parsed_cookie.secure_attribute_present = cookie.secure;
     parsed_cookie.http_only_attribute_present = cookie.http_only;
 
+    if (!cookie.host_only && cookie.domain.byte_count() > 1024)
+        return Error::from_string_literal("Cookie host exceeds the maximum size");
+
     if (!cookie.host_only)
         TRY(on_domain_attribute(parsed_cookie, cookie.domain.bytes_as_string_view()));