diff --git a/codex-rs/shell-command/src/bash.rs b/codex-rs/shell-command/src/bash.rs
index 60ee5c420c..be2f94983e 100644
--- a/codex-rs/shell-command/src/bash.rs
+++ b/codex-rs/shell-command/src/bash.rs
@@ -152,10 +152,10 @@ fn parse_plain_command_from_node(cmd: tree_sitter::Node, src: &str) -> Option<Ve
                 if word_node.kind() != "word" {
                     return None;
                 }
-                words.push(word_node.utf8_text(src.as_bytes()).ok()?.to_owned());
+                words.push(parse_unquoted_literal(word_node, src)?);
             }
             "word" | "number" => {
-                words.push(child.utf8_text(src.as_bytes()).ok()?.to_owned());
+                words.push(parse_unquoted_literal(child, src)?);
             }
             "string" => {
                 let parsed = parse_double_quoted_string(child, src)?;
@@ -172,8 +172,7 @@ fn parse_plain_command_from_node(cmd: tree_sitter::Node, src: &str) -> Option<Ve
                 for part in child.named_children(&mut concat_cursor) {
                     match part.kind() {
                         "word" | "number" => {
-                            concatenated
-                                .push_str(part.utf8_text(src.as_bytes()).ok()?.to_owned().as_str());
+                            concatenated.push_str(&parse_unquoted_literal(part, src)?);
                         }
                         "string" => {
                             let parsed = parse_double_quoted_string(part, src)?;
@@ -197,6 +196,18 @@ fn parse_plain_command_from_node(cmd: tree_sitter::Node, src: &str) -> Option<Ve
     Some(words)
 }
 
+fn parse_unquoted_literal(node: Node, src: &str) -> Option<String> {
+    let text = node.utf8_text(src.as_bytes()).ok()?;
+    if text.starts_with('~') || text.chars().any(is_unquoted_shell_expansion_char) {
+        return None;
+    }
+    Some(text.to_string())
+}
+
+fn is_unquoted_shell_expansion_char(c: char) -> bool {
+    matches!(c, '*' | '?' | '[' | ']' | '{' | '}')
+}
+
 fn parse_heredoc_command_words(cmd: Node<'_>, src: &str) -> Option<Vec<String>> {
     if cmd.kind() != "command" {
         return None;
@@ -500,6 +511,26 @@ mod tests {
         assert!(parse_seq("rg -g\"$(echo '*.py')\" pattern").is_none());
     }
 
+    #[test]
+    fn rejects_unquoted_shell_expansion_words() {
+        assert!(parse_seq("base64 -i input.txt -* cc06_out").is_none());
+        assert!(parse_seq("ls *.rs").is_none());
+        assert!(parse_seq("echo -{o,}").is_none());
+    }
+
+    #[test]
+    fn accepts_quoted_shell_expansion_literals() {
+        assert_eq!(
+            parse_seq(r#"echo "-*" '*.rs' "-{o,}""#).unwrap(),
+            vec![vec![
+                "echo".to_string(),
+                "-*".to_string(),
+                "*.rs".to_string(),
+                "-{o,}".to_string(),
+            ]]
+        );
+    }
+
     #[test]
     fn parse_shell_lc_single_command_prefix_supports_heredoc() {
         let command = vec![
diff --git a/codex-rs/shell-command/src/command_safety/is_safe_command.rs b/codex-rs/shell-command/src/command_safety/is_safe_command.rs
index b35144a12b..ae04e75c93 100644
--- a/codex-rs/shell-command/src/command_safety/is_safe_command.rs
+++ b/codex-rs/shell-command/src/command_safety/is_safe_command.rs
@@ -738,6 +738,18 @@ mod tests {
         );
     }
 
+    #[test]
+    fn bash_lc_glob_expansion_option_injection_is_not_safe() {
+        assert!(
+            !is_known_safe_command(&vec_str(&[
+                "bash",
+                "-lc",
+                "base64 -i input.txt -* cc06_out",
+            ])),
+            "Unquoted shell expansion can rewrite argv into base64 -o at runtime"
+        );
+    }
+
     #[test]
     fn direct_powershell_words_use_windows_safelist() {
         let command = vec_str(&["Get-Content", "Cargo.toml"]);