diff --git a/crates/oxc_linter/src/loader/partial_loader/vue.rs b/crates/oxc_linter/src/loader/partial_loader/vue.rs
index 2d145479eb52b..3a6a1a41a6c95 100644
--- a/crates/oxc_linter/src/loader/partial_loader/vue.rs
+++ b/crates/oxc_linter/src/loader/partial_loader/vue.rs
@@ -1,4 +1,5 @@
 use memchr::memmem::Finder;
+
 use oxc_span::SourceType;
 
 use super::{JavaScriptSource, SCRIPT_END, SCRIPT_START, find_script_closing_angle};
@@ -48,8 +49,21 @@ impl<'a> VuePartialLoader<'a> {
 
         // get ts and jsx attribute
         let content = &self.source_text[*pointer..*pointer + offset];
-        let is_ts = content.contains("ts");
-        let is_jsx = content.contains("tsx") || content.contains("jsx");
+
+        // parse `lang`
+        let lang = content.split_once("lang").map_or(Some("mjs"), |(_, s)| {
+            const QUOTES: [char; 2] = ['"', '\''];
+            s.trim_start()
+                .trim_start_matches('=')
+                .trim_start()
+                .trim_start_matches(QUOTES)
+                .split_once(QUOTES)
+                .map(|(s, _)| s)
+        })?;
+        let Ok(mut source_type) = SourceType::from_extension(lang) else { return None };
+        if !lang.contains('x') {
+            source_type = source_type.with_standard(true);
+        }
 
         *pointer += offset + 1;
         let js_start = *pointer;
@@ -61,7 +75,6 @@ impl<'a> VuePartialLoader<'a> {
         *pointer += offset + SCRIPT_END.len();
 
         let source_text = &self.source_text[js_start..js_end];
-        let source_type = SourceType::mjs().with_typescript(is_ts).with_jsx(is_jsx);
         // NOTE: loader checked that source_text.len() is less than u32::MAX
         #[expect(clippy::cast_possible_truncation)]
         Some(JavaScriptSource::partial(source_text, source_type, js_start as u32))
@@ -70,6 +83,8 @@ impl<'a> VuePartialLoader<'a> {
 
 #[cfg(test)]
 mod test {
+    use oxc_span::SourceType;
+
     use super::{JavaScriptSource, VuePartialLoader};
 
     fn parse_vue(source_text: &str) -> JavaScriptSource<'_> {
@@ -99,20 +114,7 @@ mod test {
         "#;
 
         let result = parse_vue(source_text);
-        assert!(result.source_type.is_typescript());
-        assert_eq!(result.source_text.trim(), "1/1");
-    }
-
-    #[test]
-    fn test_build_vue_with_ts_flag_2() {
-        let source_text = r"
-        <script lang=ts setup>
-            1/1
-        </script>
-        ";
-
-        let result = parse_vue(source_text);
-        assert!(result.source_type.is_typescript());
+        assert_eq!(result.source_type, SourceType::ts());
         assert_eq!(result.source_text.trim(), "1/1");
     }
 
@@ -125,21 +127,7 @@ mod test {
         ";
 
         let result = parse_vue(source_text);
-        assert!(result.source_type.is_typescript());
-        assert_eq!(result.source_text.trim(), "1/1");
-    }
-
-    #[test]
-    fn test_build_vue_with_tsx_flag() {
-        let source_text = r"
-        <script lang=tsx setup>
-            1/1
-        </script>
-        ";
-
-        let result = parse_vue(source_text);
-        assert!(result.source_type.is_jsx());
-        assert!(result.source_type.is_typescript());
+        assert_eq!(result.source_type, SourceType::ts());
         assert_eq!(result.source_text.trim(), "1/1");
     }
 
@@ -252,4 +240,28 @@ mod test {
         assert_eq!(sources.len(), 1);
         assert_eq!(sources[0].source_text, "a");
     }
+
+    #[test]
+    fn lang() {
+        let cases = [
+            ("<script>debugger</script>", Some(SourceType::mjs())),
+            ("<script lang = 'tsx' >debugger</script>", Some(SourceType::tsx())),
+            (r#"<script lang = "cjs" >debugger</script>"#, Some(SourceType::cjs())),
+            ("<script lang = 'xxx'>debugger</script>", None),
+            (r#"<script lang = "xxx">debugger</script>"#, None),
+            ("<script lang='xxx'>debugger</script>", None),
+            (r#"<script lang="xxx">debugger</script>"#, None),
+            ("<script lang=tsx>debugger</script>", None), // this is valid but too compliated to parse
+        ];
+
+        for (source_text, source_type) in cases {
+            let sources = VuePartialLoader::new(source_text).parse();
+            if let Some(expected) = source_type {
+                assert_eq!(sources.len(), 1);
+                assert_eq!(sources[0].source_type, expected);
+            } else {
+                assert_eq!(sources.len(), 0);
+            }
+        }
+    }
 }
diff --git a/crates/oxc_span/src/source_type/mod.rs b/crates/oxc_span/src/source_type/mod.rs
index e672488e5c36a..4a081783921ad 100644
--- a/crates/oxc_span/src/source_type/mod.rs
+++ b/crates/oxc_span/src/source_type/mod.rs
@@ -462,36 +462,44 @@ impl SourceType {
                 )
             })?;
 
+        let mut source_type = Self::from_extension(extension)?;
+
+        #[expect(clippy::case_sensitive_file_extension_comparisons)]
+        if match extension {
+            "ts" if file_name[..file_name.len() - 3].split('.').rev().take(2).any(|c| c == "d") => {
+                true
+            }
+            "mts" | "cts" if file_name[..file_name.len() - 4].ends_with(".d") => true,
+            _ => false,
+        } {
+            source_type.language = Language::TypeScriptDefinition;
+        }
+
+        Ok(source_type)
+    }
+
+    /// Converts a file extension to [`SourceType`].
+    ///
+    /// # Errors
+    ///
+    /// Returns [`UnknownExtension`] if:
+    ///   * the file extension is not one of "js", "mjs", "cjs", "jsx", "ts",
+    ///     "mts", "cts", "tsx". See [`VALID_EXTENSIONS`] for the list of valid
+    ///     extensions.
+    pub fn from_extension(extension: &str) -> Result<Self, UnknownExtension> {
         let module_kind = match extension {
             "js" | "tsx" | "ts" | "jsx" | "mts" | "mjs" => ModuleKind::Module,
             "cjs" | "cts" => ModuleKind::Script,
-            _ => unreachable!(),
+            _ => return Err(UnknownExtension::new("Unknown extension.")),
         };
 
         let language = match extension {
             // https://www.typescriptlang.org/tsconfig/#allowArbitraryExtensions
             // `{file basename}.d.{extension}.ts`
             // https://github.com/microsoft/TypeScript/issues/50133
-            "ts" => {
-                if file_name[..file_name.len() - 3].split('.').rev().take(2).any(|c| c == "d") {
-                    Language::TypeScriptDefinition
-                } else {
-                    Language::TypeScript
-                }
-            }
             "js" | "cjs" | "mjs" | "jsx" => Language::JavaScript,
-            "tsx" => Language::TypeScript,
-            #[expect(clippy::case_sensitive_file_extension_comparisons)]
-            "mts" | "cts" => {
-                if file_name[..file_name.len() - 4].ends_with(".d") {
-                    Language::TypeScriptDefinition
-                } else {
-                    Language::TypeScript
-                }
-            }
-            _ => {
-                unreachable!();
-            }
+            "ts" | "tsx" | "mts" | "cts" => Language::TypeScript,
+            _ => return Err(UnknownExtension::new("Unknown extension.")),
         };
 
         let variant = match extension {