From 70eafc29534fe0e0b377f41a11687574caa491db Mon Sep 17 00:00:00 2001
From: Maurelian <maurelian@protonmail.ch>
Date: Wed, 7 Oct 2026 18:49:08 -0400
Subject: [PATCH] fix(StdCheats): exclude P256VERIFY precompile in
 assumeNotPrecompile

assumeNotPrecompile only excluded 0x01-0xff, so fuzzers could pick 0x100,
the P256VERIFY precompile added in Osaka (EIP-7951).
---
 src/StdCheats.sol    |  3 ++-
 test/StdCheats.t.sol | 14 +++++++++++++-
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/src/StdCheats.sol b/src/StdCheats.sol
index 95a5bf95..cc12f121 100644
--- a/src/StdCheats.sol
+++ b/src/StdCheats.sol
@@ -327,7 +327,8 @@ abstract contract StdCheatsSafe {
         // address), but the same rationale for excluding them applies so we include those too.
 
         // These are reserved by Ethereum and may be on all EVM-compatible chains.
-        vm.assume(addr < address(0x1) || addr > address(0xff));
+        // 0x100 is P256VERIFY (EIP-7951).
+        vm.assume(addr < address(0x1) || addr > address(0x100));
 
         // forgefmt: disable-start
         if (chainId == 10 || chainId == 420 || chainId == 11155420) {
diff --git a/test/StdCheats.t.sol b/test/StdCheats.t.sol
index 868829dd..99c1396d 100644
--- a/test/StdCheats.t.sol
+++ b/test/StdCheats.t.sol
@@ -401,11 +401,19 @@ contract StdCheatsTest is Test {
     function testFuzz_AssumeNotPrecompile(address addr) external {
         assumeNotPrecompile(addr, getChain("optimism_sepolia").chainId);
         assertTrue(
-            addr < address(1) || (addr > address(9) && addr < address(0x4200000000000000000000000000000000000000))
+            addr < address(1) || (addr > address(0x100) && addr < address(0x4200000000000000000000000000000000000000))
                 || addr > address(0x4200000000000000000000000000000000000800)
         );
     }
 
+    function test_AssumeNotPrecompileP256Verify() external {
+        StdCheatsMock stdCheatsMock = new StdCheatsMock();
+
+        // P256VERIFY (EIP-7951)
+        vm.expectRevert();
+        stdCheatsMock.exposedAssumeNotPrecompile(address(0x100));
+    }
+
     function testFuzz_AssumeNotForgeAddress(address addr) external pure {
         assumeNotForgeAddress(addr);
         assertTrue(
@@ -508,6 +516,10 @@ contract StdCheatsMock is StdCheats {
     function exposedAssumeNotBlacklisted(address token, address addr) external view {
         return assumeNotBlacklisted(token, addr);
     }
+
+    function exposedAssumeNotPrecompile(address addr) external pure {
+        assumeNotPrecompile(addr);
+    }
 }
 
 contract StdCheatsForkTest is Test {