diff --git a/lib/markdown2.py b/lib/markdown2.py
index 3632a54e..f63f2ef0 100755
--- a/lib/markdown2.py
+++ b/lib/markdown2.py
@@ -1581,6 +1581,20 @@ def _find_balanced(self, text: str, start: int, open_c: str, close_c: str) -> in
         out - the same number of open_c and close_c are encountered - or the
         end of string if it's reached before the balance point is found.
         """
+        # If no `close_c` remains in the text, the loop below runs to the end,
+        # and the link scanner calls this once per `[...](`, which is quadratic
+        # for unclosed brackets. Skip the scan using a per-text cache of the
+        # last `close_c` position.
+        cache = getattr(self, "_balanced_last_close", None)
+        if cache is None or cache[0] is not text:
+            cache = [text, {}]
+            self._balanced_last_close = cache
+        last = cache[1].get(close_c)
+        if last is None:
+            last = text.rfind(close_c)
+            cache[1][close_c] = last
+        if start > last:
+            return len(text)
         i = start
         l = len(text)
         count = 1
@@ -3157,6 +3171,10 @@ def parse_inline_anchor_or_image(self, text: str, _link_text: str, start_idx: in
         if has_anglebrackets:
             end_idx = self.md._find_balanced(text, end_idx+1, "<", ">")
         end_idx = self.md._find_balanced(text, end_idx, "(", ")")
+        if text[end_idx - 1] != ")":
+            # The destination's "(" never closed, so `_inline_link_title` (which
+            # ends in `\)$`) cannot match; skip the search.
+            return
         match = self.md._inline_link_title.search(text, idx, end_idx)
         if not match:
             return
diff --git a/test/tm-cases/unclosed_link_parens.html b/test/tm-cases/unclosed_link_parens.html
new file mode 100644
index 00000000..c6dee763
--- /dev/null
+++ b/test/tm-cases/unclosed_link_parens.html
@@ -0,0 +1,409 @@
+<p>[a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
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+
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+<p>![img](</p>
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+<p>![img](</p>
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+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>![img](</p>
+
+<p>[c](unclosed</p>
+
+<p>[d](<unclosed scheme</p>
+
+<p>[e](a(b)c</p>
+
+<p>A valid <a href="http://example.com">ok</a> link, a <a href="http://example.com" title="Title">titled</a> link, and a <a href="http://example.com/a(b)c">nested</a> one.</p>
diff --git a/test/tm-cases/unclosed_link_parens.text b/test/tm-cases/unclosed_link_parens.text
new file mode 100644
index 00000000..e4b5a263
--- /dev/null
+++ b/test/tm-cases/unclosed_link_parens.text
@@ -0,0 +1,409 @@
+[a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a]([a](
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+![img](
+
+![img](
+
+![img](
+
+![img](
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+![img](
+
+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+![img](
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+[c](unclosed
+
+[d](<unclosed scheme
+
+[e](a(b)c
+
+A valid [ok](http://example.com) link, a [titled](http://example.com "Title") link, and a [nested](http://example.com/a(b)c) one.