Fix out-of-bounds check

src/main.cpp

@@ -2443,7 +2443,8 @@ bool AcceptBlock(CBlock& block, CValidationState& state, CDiskBlockPos* dbp)
                 (TestNet() && CBlockIndex::IsSuperMajority(2, pindexPrev, 51, 100)))
             {
                 CScript expect = CScript() << nHeight;
-                if (!std::equal(expect.begin(), expect.end(), block.vtx[0].vin[0].scriptSig.begin()))
+                if (block.vtx[0].vin[0].scriptSig.size() < expect.size() ||
+                    !std::equal(expect.begin(), expect.end(), block.vtx[0].vin[0].scriptSig.begin()))
                     return state.DoS(100, error("AcceptBlock() : block height mismatch in coinbase"));
             }
         }