diff --git a/Cargo.lock b/Cargo.lock
index 03fbed6d3c5..b6caf028441 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -277,7 +277,7 @@ dependencies = [
 name = "common-types"
 version = "0.1.0"
 dependencies = [
- "ethcore-util 1.7.5",
+ "ethcore-util 1.7.6",
  "ethjson 0.1.0",
  "rlp 0.2.0",
  "rustc-hex 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -476,7 +476,7 @@ dependencies = [
  "ethcore-ipc-nano 1.7.0",
  "ethcore-logger 1.7.0",
  "ethcore-stratum 1.7.0",
- "ethcore-util 1.7.5",
+ "ethcore-util 1.7.6",
  "ethjson 0.1.0",
  "ethkey 0.2.0",
  "ethstore 0.1.0",
@@ -545,7 +545,7 @@ name = "ethcore-ipc"
 version = "1.7.0"
 dependencies = [
  "ethcore-devtools 1.7.0",
- "ethcore-util 1.7.5",
+ "ethcore-util 1.7.6",
  "nanomsg 0.5.1 (git+https://github.com/paritytech/nanomsg.rs.git?branch=parity-1.7)",
  "semver 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -594,7 +594,7 @@ dependencies = [
  "ethcore-ipc 1.7.0",
  "ethcore-ipc-codegen 1.7.0",
  "ethcore-ipc-nano 1.7.0",
- "ethcore-util 1.7.5",
+ "ethcore-util 1.7.6",
  "log 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "nanomsg 0.5.1 (git+https://github.com/paritytech/nanomsg.rs.git?branch=parity-1.7)",
  "semver 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -611,7 +611,7 @@ dependencies = [
  "ethcore-ipc 1.7.0",
  "ethcore-ipc-codegen 1.7.0",
  "ethcore-network 1.7.0",
- "ethcore-util 1.7.5",
+ "ethcore-util 1.7.6",
  "evm 0.1.0",
  "futures 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "itertools 0.5.9 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -650,7 +650,7 @@ dependencies = [
  "ethcore-devtools 1.7.0",
  "ethcore-io 1.7.0",
  "ethcore-logger 1.7.0",
- "ethcore-util 1.7.5",
+ "ethcore-util 1.7.6",
  "ethcrypto 0.1.0",
  "ethkey 0.2.0",
  "igd 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -681,7 +681,7 @@ dependencies = [
  "ethcore-ipc-codegen 1.7.0",
  "ethcore-ipc-nano 1.7.0",
  "ethcore-logger 1.7.0",
- "ethcore-util 1.7.5",
+ "ethcore-util 1.7.6",
  "ethcrypto 0.1.0",
  "ethkey 0.2.0",
  "futures 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -711,7 +711,7 @@ dependencies = [
  "ethcore-ipc-codegen 1.7.0",
  "ethcore-ipc-nano 1.7.0",
  "ethcore-logger 1.7.0",
- "ethcore-util 1.7.5",
+ "ethcore-util 1.7.6",
  "futures 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "jsonrpc-core 7.0.0 (git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7)",
  "jsonrpc-macros 7.0.0 (git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7)",
@@ -724,7 +724,7 @@ dependencies = [
 
 [[package]]
 name = "ethcore-util"
-version = "1.7.5"
+version = "1.7.6"
 dependencies = [
  "ansi_term 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "clippy 0.0.103 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -774,7 +774,7 @@ name = "ethjson"
 version = "0.1.0"
 dependencies = [
  "clippy 0.0.103 (registry+https://github.com/rust-lang/crates.io-index)",
- "ethcore-util 1.7.5",
+ "ethcore-util 1.7.6",
  "rustc-hex 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -855,7 +855,7 @@ dependencies = [
  "ethcore-ipc-nano 1.7.0",
  "ethcore-light 1.7.0",
  "ethcore-network 1.7.0",
- "ethcore-util 1.7.5",
+ "ethcore-util 1.7.6",
  "ethkey 0.2.0",
  "heapsize 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -874,7 +874,7 @@ dependencies = [
  "bit-set 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "byteorder 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "common-types 0.1.0",
- "ethcore-util 1.7.5",
+ "ethcore-util 1.7.6",
  "ethjson 0.1.0",
  "evmjit 1.7.0",
  "lazy_static 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -891,7 +891,7 @@ version = "0.1.0"
 dependencies = [
  "docopt 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "ethcore 1.7.0",
- "ethcore-util 1.7.5",
+ "ethcore-util 1.7.6",
  "ethjson 0.1.0",
  "evm 0.1.0",
  "rustc-hex 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1136,7 +1136,7 @@ version = "1.7.0"
 dependencies = [
  "ethcore-ipc 1.7.0",
  "ethcore-ipc-codegen 1.7.0",
- "ethcore-util 1.7.5",
+ "ethcore-util 1.7.6",
  "semver 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -1530,7 +1530,7 @@ version = "0.1.0"
 dependencies = [
  "byteorder 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "ethabi 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "ethcore-util 1.7.5",
+ "ethcore-util 1.7.6",
  "futures 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "native-contract-generator 0.1.0",
 ]
@@ -1735,7 +1735,7 @@ dependencies = [
 
 [[package]]
 name = "parity"
-version = "1.7.5"
+version = "1.7.6"
 dependencies = [
  "ansi_term 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "app_dirs 1.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1755,7 +1755,7 @@ dependencies = [
  "ethcore-logger 1.7.0",
  "ethcore-secretstore 1.0.0",
  "ethcore-stratum 1.7.0",
- "ethcore-util 1.7.5",
+ "ethcore-util 1.7.6",
  "ethkey 0.2.0",
  "ethsync 1.7.0",
  "fdlimit 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1801,7 +1801,7 @@ dependencies = [
  "clippy 0.0.103 (registry+https://github.com/rust-lang/crates.io-index)",
  "env_logger 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "ethcore-devtools 1.7.0",
- "ethcore-util 1.7.5",
+ "ethcore-util 1.7.6",
  "fetch 0.1.0",
  "futures 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "jsonrpc-core 7.0.0 (git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7)",
@@ -1845,7 +1845,7 @@ name = "parity-hash-fetch"
 version = "1.7.0"
 dependencies = [
  "ethabi 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "ethcore-util 1.7.5",
+ "ethcore-util 1.7.6",
  "fetch 0.1.0",
  "futures 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1863,7 +1863,7 @@ version = "1.7.0"
 dependencies = [
  "cid 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "ethcore 1.7.0",
- "ethcore-util 1.7.5",
+ "ethcore-util 1.7.6",
  "jsonrpc-http-server 7.0.0 (git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7)",
  "mime 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "multihash 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1876,7 +1876,7 @@ version = "0.1.0"
 dependencies = [
  "ethcore 1.7.0",
  "ethcore-io 1.7.0",
- "ethcore-util 1.7.5",
+ "ethcore-util 1.7.6",
  "ethkey 0.2.0",
  "log 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "rlp 0.2.0",
@@ -1906,7 +1906,7 @@ dependencies = [
  "ethcore-ipc 1.7.0",
  "ethcore-light 1.7.0",
  "ethcore-logger 1.7.0",
- "ethcore-util 1.7.5",
+ "ethcore-util 1.7.6",
  "ethcrypto 0.1.0",
  "ethjson 0.1.0",
  "ethkey 0.2.0",
@@ -1948,7 +1948,7 @@ dependencies = [
 name = "parity-rpc-client"
 version = "1.4.0"
 dependencies = [
- "ethcore-util 1.7.5",
+ "ethcore-util 1.7.6",
  "futures 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "jsonrpc-core 7.0.0 (git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7)",
  "jsonrpc-ws-server 7.0.0 (git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7)",
@@ -2011,7 +2011,7 @@ dependencies = [
  "ethcore 1.7.0",
  "ethcore-ipc 1.7.0",
  "ethcore-ipc-codegen 1.7.0",
- "ethcore-util 1.7.5",
+ "ethcore-util 1.7.6",
  "ethsync 1.7.0",
  "futures 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "ipc-common-types 1.7.0",
@@ -2367,7 +2367,7 @@ name = "rpc-cli"
 version = "1.4.0"
 dependencies = [
  "bigint 3.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "ethcore-util 1.7.5",
+ "ethcore-util 1.7.6",
  "futures 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-rpc 1.7.0",
  "parity-rpc-client 1.4.0",
diff --git a/Cargo.toml b/Cargo.toml
index ecd83513e23..88e20a63168 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 description = "Parity Ethereum client"
 name = "parity"
-version = "1.7.5"
+version = "1.7.6"
 license = "GPL-3.0"
 authors = ["Parity Technologies <admin@parity.io>"]
 build = "build.rs"
diff --git a/ethcore/src/builtin.rs b/ethcore/src/builtin.rs
index d1d4148fce2..941618f9c3f 100644
--- a/ethcore/src/builtin.rs
+++ b/ethcore/src/builtin.rs
@@ -120,7 +120,11 @@ impl Pricer for ModexpPricer {
 
 		let adjusted_exp_len = Self::adjusted_exp_len(exp_len, exp_low);
 
-		(Self::mult_complexity(m) * max(adjusted_exp_len, 1) / self.divisor as u64).into()
+		let (gas, overflow) = Self::mult_complexity(m).overflowing_mul(max(adjusted_exp_len, 1));
+		if overflow {
+			return U256::max_value();
+		}
+		(gas / self.divisor as u64).into()
 	}
 }
 
@@ -711,6 +715,14 @@ mod tests {
 			activate_at: 0,
 		};
 
+		// test for potential gas cost multiplication overflow
+		{
+			let input = FromHex::from_hex("0000000000000000000000000000000000000000000000000000000000000001000000000000000000000000000000000000000000000000000000003b27bafd00000000000000000000000000000000000000000000000000000000503c8ac3").unwrap();
+			let expected_cost = U256::max_value();
+			assert_eq!(f.cost(&input[..]), expected_cost.into());
+		}
+
+
 		// test for potential exp len overflow
 		{
 			let input = FromHex::from_hex("\
diff --git a/mac/Parity.pkgproj b/mac/Parity.pkgproj
index 53cd2b8717c..2c9c12a80ab 100755
--- a/mac/Parity.pkgproj
+++ b/mac/Parity.pkgproj
@@ -462,7 +462,7 @@
 				<key>OVERWRITE_PERMISSIONS</key>
 				<false/>
 				<key>VERSION</key>
-				<string>1.7.5</string>
+				<string>1.7.6</string>
 			</dict>
 			<key>UUID</key>
 			<string>2DCD5B81-7BAF-4DA1-9251-6274B089FD36</string>
diff --git a/nsis/installer.nsi b/nsis/installer.nsi
index 5ad74534a25..a66aae18761 100644
--- a/nsis/installer.nsi
+++ b/nsis/installer.nsi
@@ -10,7 +10,7 @@
 !define DESCRIPTION "Fast, light, robust Ethereum implementation"
 !define VERSIONMAJOR 1
 !define VERSIONMINOR 7
-!define VERSIONBUILD 5
+!define VERSIONBUILD 6
 !define ARGS "--warp"
 !define FIRST_START_ARGS "ui --warp --mode=passive"
 
diff --git a/util/Cargo.toml b/util/Cargo.toml
index 7caed66aa18..a15057f10f5 100644
--- a/util/Cargo.toml
+++ b/util/Cargo.toml
@@ -3,7 +3,7 @@ description = "Ethcore utility library"
 homepage = "http://parity.io"
 license = "GPL-3.0"
 name = "ethcore-util"
-version = "1.7.5"
+version = "1.7.6"
 authors = ["Parity Technologies <admin@parity.io>"]
 build = "build.rs"