diff --git a/math/lemon/files/patch-CMakeLists.txt b/math/lemon/files/patch-CMakeLists.txt
new file mode 100644
index 000000000000..e445e2bcd5a8
--- /dev/null
+++ b/math/lemon/files/patch-CMakeLists.txt
@@ -0,0 +1,15 @@
+-- Fix configure with CMake 4 by raising the minimum required CMake version
+-- from 2.8 to 3.5 and removing the obsolete CMP0048 policy override.
+-- CMake 4 no longer supports compatibility with CMake versions below 3.5
+-- and removed the OLD behavior of CMP0048.
+
+--- CMakeLists.txt.orig	2014-07-07 14:40:24 UTC
++++ CMakeLists.txt
+@@ -1,6 +1,4 @@
+-CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
+-
+-CMAKE_POLICY(SET CMP0048 OLD)
++CMAKE_MINIMUM_REQUIRED(VERSION 3.5)
+
+ SET(PROJECT_NAME "LEMON")
+ PROJECT(${PROJECT_NAME})
diff --git a/math/lemon/files/patch-lemon_bits_array__map.h b/math/lemon/files/patch-lemon_bits_array__map.h
index 404c1faba292..a62c080157e4 100644
--- a/math/lemon/files/patch-lemon_bits_array__map.h
+++ b/math/lemon/files/patch-lemon_bits_array__map.h
@@ -1,108 +1,108 @@
 -- Replace deprecated std::allocator::construct/destroy (removed in C++20) with
 -- placement new and explicit destructor calls. These are compatible with C++11
 -- through C++26 and fix compilation of C++20 consumers of LEMON (e.g. OpenROAD).
 
---- lemon/bits/array_map.h.orig
+--- lemon/bits/array_map.h.orig	2014-07-07 14:40:24 UTC
 +++ lemon/bits/array_map.h
-@@ -88,7 +88,7 @@
+@@ -88,7 +88,7 @@ namespace lemon {
        Item it;
        for (nf->first(it); it != INVALID; nf->next(it)) {
          int id = nf->id(it);;
 -        allocator.construct(&(values[id]), Value());
 +        ::new(static_cast<void*>(&(values[id]))) Value();
        }
      }
  
-@@ -102,7 +102,7 @@
+@@ -102,7 +102,7 @@ namespace lemon {
        Item it;
        for (nf->first(it); it != INVALID; nf->next(it)) {
          int id = nf->id(it);;
 -        allocator.construct(&(values[id]), value);
 +        ::new(static_cast<void*>(&(values[id]))) Value(value);
        }
      }
  
-@@ -121,7 +121,7 @@
+@@ -121,7 +121,7 @@ namespace lemon {
        Item it;
        for (nf->first(it); it != INVALID; nf->next(it)) {
          int id = nf->id(it);;
 -        allocator.construct(&(values[id]), copy.values[id]);
 +        ::new(static_cast<void*>(&(values[id]))) Value(copy.values[id]);
        }
      }
  
-@@ -218,15 +218,15 @@
+@@ -218,15 +218,15 @@ namespace lemon {
          for (nf->first(it); it != INVALID; nf->next(it)) {
            int jd = nf->id(it);;
            if (id != jd) {
 -            allocator.construct(&(new_values[jd]), values[jd]);
 -            allocator.destroy(&(values[jd]));
 +            ::new(static_cast<void*>(&(new_values[jd]))) Value(values[jd]);
 +            values[jd].~Value();
            }
          }
          if (capacity != 0) allocator.deallocate(values, capacity);
          values = new_values;
          capacity = new_capacity;
        }
 -      allocator.construct(&(values[id]), Value());
 +      ::new(static_cast<void*>(&(values[id]))) Value();
      }
  
      // \brief Adds more new keys to the map.
-@@ -260,8 +260,8 @@
+@@ -260,8 +260,8 @@ namespace lemon {
              }
            }
            if (found) continue;
 -          allocator.construct(&(new_values[id]), values[id]);
 -          allocator.destroy(&(values[id]));
 +          ::new(static_cast<void*>(&(new_values[id]))) Value(values[id]);
 +          values[id].~Value();
          }
          if (capacity != 0) allocator.deallocate(values, capacity);
          values = new_values;
-@@ -269,7 +269,7 @@
+@@ -269,7 +269,7 @@ namespace lemon {
        }
        for (int i = 0; i < int(keys.size()); ++i) {
          int id = nf->id(keys[i]);
 -        allocator.construct(&(values[id]), Value());
 +        ::new(static_cast<void*>(&(values[id]))) Value();
        }
      }
  
-@@ -279,7 +279,7 @@
+@@ -279,7 +279,7 @@ namespace lemon {
      // and it overrides the erase() member function of the observer base.
      virtual void erase(const Key& key) {
        int id = Parent::notifier()->id(key);
 -      allocator.destroy(&(values[id]));
 +      values[id].~Value();
      }
  
      // \brief Erase more keys from the map.
-@@ -289,7 +289,7 @@
+@@ -289,7 +289,7 @@ namespace lemon {
      virtual void erase(const std::vector<Key>& keys) {
        for (int i = 0; i < int(keys.size()); ++i) {
          int id = Parent::notifier()->id(keys[i]);
 -        allocator.destroy(&(values[id]));
 +        values[id].~Value();
        }
      }
  
-@@ -303,7 +303,7 @@
+@@ -303,7 +303,7 @@ namespace lemon {
        Item it;
        for (nf->first(it); it != INVALID; nf->next(it)) {
          int id = nf->id(it);;
 -        allocator.construct(&(values[id]), Value());
 +        ::new(static_cast<void*>(&(values[id]))) Value();
        }
      }
  
-@@ -317,7 +317,7 @@
+@@ -317,7 +317,7 @@ namespace lemon {
          Item it;
          for (nf->first(it); it != INVALID; nf->next(it)) {
            int id = nf->id(it);
 -          allocator.destroy(&(values[id]));
 +          values[id].~Value();
          }
          allocator.deallocate(values, capacity);
          capacity = 0;
diff --git a/math/lemon/files/patch-lemon_network__simplex.h b/math/lemon/files/patch-lemon_network__simplex.h
index 1be67435f9f7..2533fcd0ef8c 100644
--- a/math/lemon/files/patch-lemon_network__simplex.h
+++ b/math/lemon/files/patch-lemon_network__simplex.h
@@ -1,24 +1,24 @@
 -- Guard the NetworkSimplex class against the MAX(a,b) macro defined by FreeBSD system
 -- headers via <sys/param.h>. LEMON uses MAX as a member variable name; the macro
 -- expansion corrupts the constructor initializer list in C++20 code.
 -- Uses #pragma push_macro/pop_macro, supported by GCC, Clang and MSVC.
 
---- lemon/network_simplex.h.orig
+--- lemon/network_simplex.h.orig	2014-07-07 14:40:24 UTC
 +++ lemon/network_simplex.h
-@@ -71,6 +71,8 @@
+@@ -71,6 +71,8 @@ namespace lemon {
    /// \note %NetworkSimplex provides five different pivot rule
    /// implementations, from which the most efficient one is used
    /// by default. For more information, see \ref PivotRule.
 +#pragma push_macro("MAX")
 +#undef MAX
    template <typename GR, typename V = int, typename C = V>
    class NetworkSimplex
    {
-@@ -1651,6 +1653,7 @@
+@@ -1651,6 +1653,7 @@ namespace lemon {
      }
  
    }; //class NetworkSimplex
 +#pragma pop_macro("MAX")
  
    ///@}