diff --git a/CHANGELOG.md b/CHANGELOG.md
index 80a1fbe6..1bbe8204 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,62 @@ All notable changes to Zebra will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/), and this project adheres to [Semantic Versioning](https://semver.org).
 
+## [Zebra 1.0.0-alpha.18](https://github.com/ZcashFoundation/zebra/releases/tag/v1.0.0-alpha.18) - 2021-10-05
+
+Zebra's latest alpha updates dependencies, consensus parameters, and Orchard for NU5 testnet activation.
+It continues our work on the mempool, including some mempool features that are used during network upgrade activation.
+
+### Added
+
+#### Mempool
+
+- Send crawled transaction IDs to the mempool downloader (#2801)
+- Cancel mempool download tasks when a network upgrade activates (#2816)
+- Send mined transaction IDs to the mempool download/verify task for cancellation (#2786)
+- Remove expired transactions from the mempool (#2774)
+- Cancel download and verify tasks when the mempool is deactivated (#2764, #2754)
+- Reject mempool transactions with conflicting spends (#2765)
+- Clear mempool at a network upgrade (#2773, #2785)
+
+#### Network Upgrade 5
+
+- Update Zebra's advertised network protocol version to the latest NU5 testnet version (#2803)
+
+#### Testing and CI
+
+- Add tests to ensure mempool is working correctly (#2769, #2770, #2815)
+- Create and use a helper MockService type to help with writing tests (#2810, #2748, #2790)
+- Update Zebra tests to use the NU5 testnet activation height (#2802)
+- Regenerate NU5 test cases with the latest network upgrade parameters (#2802)
+
+#### Metrics
+
+- Add Zebra metrics and a Grafana dashboard for connected peers and their network protocol versions (#2804, #2811)
+
+### Changed
+
+- Stop sending empty network messages to peers (#2791)
+- Correctly validate transactions which never expire (#2782)
+
+#### Network Upgrade 5
+
+- Update `zcash_script` dependency to support V5 transactions (#2825)
+- Set the NU5 testnet activation network upgrade parameters (#2802)
+- Update shared Zcash Rust NU5 dependencies  (#2739)
+- Update Zebra to use modified APIs in shared Zcash Rust NU5 dependencies (#2739)
+
+### Fixed
+
+- Stop panicking when using sync and async methods on the same `ChainTipChange` (#2800)
+- Fix an incorrect assertion when the block locator is at the tip (#2789)
+- Fix a missing NULL pointer check in `zebra_script`'s FFI (#2802)
+
+### Security
+
+#### Network Upgrade 5
+
+- Update Zebra's orchard commitment calculations based on the latest orchard circuit (#2807)
+
 ## [Zebra 1.0.0-alpha.17](https://github.com/ZcashFoundation/zebra/releases/tag/v1.0.0-alpha.17) - 2021-09-14
 
 Zebra's latest alpha continues work on the mempool.
diff --git a/Cargo.lock b/Cargo.lock
index 2a35138d..73823c25 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3985,7 +3985,7 @@ dependencies = [
 
 [[package]]
 name = "tower-batch"
-version = "0.2.13"
+version = "0.2.14"
 dependencies = [
  "color-eyre",
  "ed25519-zebra",
@@ -4005,7 +4005,7 @@ dependencies = [
 
 [[package]]
 name = "tower-fallback"
-version = "0.2.11"
+version = "0.2.12"
 dependencies = [
  "futures-core",
  "pin-project 0.4.28",
@@ -4752,7 +4752,7 @@ dependencies = [
 
 [[package]]
 name = "zebra-chain"
-version = "1.0.0-alpha.17"
+version = "1.0.0-alpha.18"
 dependencies = [
  "aes 0.6.0",
  "bech32",
@@ -4807,7 +4807,7 @@ version = "1.0.0-alpha.0"
 
 [[package]]
 name = "zebra-consensus"
-version = "1.0.0-alpha.17"
+version = "1.0.0-alpha.18"
 dependencies = [
  "bellman",
  "blake2b_simd",
@@ -4845,7 +4845,7 @@ dependencies = [
 
 [[package]]
 name = "zebra-network"
-version = "1.0.0-alpha.17"
+version = "1.0.0-alpha.18"
 dependencies = [
  "bitflags",
  "byteorder",
@@ -4880,7 +4880,7 @@ version = "1.0.0-alpha.0"
 
 [[package]]
 name = "zebra-script"
-version = "1.0.0-alpha.18"
+version = "1.0.0-alpha.19"
 dependencies = [
  "displaydoc",
  "hex",
@@ -4893,7 +4893,7 @@ dependencies = [
 
 [[package]]
 name = "zebra-state"
-version = "1.0.0-alpha.17"
+version = "1.0.0-alpha.18"
 dependencies = [
  "bincode",
  "chrono",
@@ -4927,7 +4927,7 @@ dependencies = [
 
 [[package]]
 name = "zebra-test"
-version = "1.0.0-alpha.14"
+version = "1.0.0-alpha.15"
 dependencies = [
  "color-eyre",
  "futures 0.3.17",
@@ -4951,7 +4951,7 @@ dependencies = [
 
 [[package]]
 name = "zebra-utils"
-version = "1.0.0-alpha.17"
+version = "1.0.0-alpha.18"
 dependencies = [
  "color-eyre",
  "hex",
@@ -4966,7 +4966,7 @@ dependencies = [
 
 [[package]]
 name = "zebrad"
-version = "1.0.0-alpha.17"
+version = "1.0.0-alpha.18"
 dependencies = [
  "abscissa_core",
  "atty",
diff --git a/README.md b/README.md
index 96032226..185c7c02 100644
--- a/README.md
+++ b/README.md
@@ -40,7 +40,7 @@ Building `zebrad` requires [Rust](https://www.rust-lang.org/tools/install),
 2. Install Zebra's build dependencies:
      - **libclang:** the `libclang`, `libclang-dev`, `llvm`, or `llvm-dev` packages, depending on your package manager
      - **clang** or another C++ compiler: `g++`, `Xcode`, or `MSVC`
-3. Run `cargo install --locked --git https://github.com/ZcashFoundation/zebra --tag v1.0.0-alpha.17 zebrad`
+3. Run `cargo install --locked --git https://github.com/ZcashFoundation/zebra --tag v1.0.0-alpha.18 zebrad`
 4. Run `zebrad start`
 
 If you're interested in testing out `zebrad` please feel free, but keep in mind
diff --git a/tower-batch/Cargo.toml b/tower-batch/Cargo.toml
index b11de579..cba6a3fe 100644
--- a/tower-batch/Cargo.toml
+++ b/tower-batch/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "tower-batch"
-version = "0.2.13"
+version = "0.2.14"
 authors = ["Zcash Foundation <zebra@zfnd.org>"]
 license = "MIT"
 edition = "2018"
diff --git a/tower-fallback/Cargo.toml b/tower-fallback/Cargo.toml
index 0c4b0a18..0bae1ad7 100644
--- a/tower-fallback/Cargo.toml
+++ b/tower-fallback/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "tower-fallback"
-version = "0.2.11"
+version = "0.2.12"
 authors = ["Zcash Foundation <zebra@zfnd.org>"]
 license = "MIT"
 edition = "2018"
diff --git a/zebra-chain/Cargo.toml b/zebra-chain/Cargo.toml
index 7a351d36..ff36a40d 100644
--- a/zebra-chain/Cargo.toml
+++ b/zebra-chain/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "zebra-chain"
-version = "1.0.0-alpha.17"
+version = "1.0.0-alpha.18"
 authors = ["Zcash Foundation <zebra@zfnd.org>"]
 license = "MIT OR Apache-2.0"
 edition = "2018"
diff --git a/zebra-consensus/Cargo.toml b/zebra-consensus/Cargo.toml
index f66ca927..c63abc21 100644
--- a/zebra-consensus/Cargo.toml
+++ b/zebra-consensus/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "zebra-consensus"
-version = "1.0.0-alpha.17"
+version = "1.0.0-alpha.18"
 authors = ["Zcash Foundation <zebra@zfnd.org>"]
 license = "MIT OR Apache-2.0"
 edition = "2018"
diff --git a/zebra-network/Cargo.toml b/zebra-network/Cargo.toml
index c3479414..e0f61d44 100644
--- a/zebra-network/Cargo.toml
+++ b/zebra-network/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "zebra-network"
-version = "1.0.0-alpha.17"
+version = "1.0.0-alpha.18"
 authors = ["Zcash Foundation <zebra@zfnd.org>"]
 license = "MIT OR Apache-2.0"
 edition = "2018"
diff --git a/zebra-network/src/constants.rs b/zebra-network/src/constants.rs
index b93328a2..27131236 100644
--- a/zebra-network/src/constants.rs
+++ b/zebra-network/src/constants.rs
@@ -106,7 +106,7 @@ pub const TIMESTAMP_TRUNCATION_SECONDS: u32 = 30 * 60;
 /// [BIP 14]: https://github.com/bitcoin/bips/blob/master/bip-0014.mediawiki
 //
 // TODO: generate this from crate metadata (#2375)
-pub const USER_AGENT: &str = "/Zebra:1.0.0-alpha.17/";
+pub const USER_AGENT: &str = "/Zebra:1.0.0-alpha.18/";
 
 /// The Zcash network protocol version implemented by this crate, and advertised
 /// during connection setup.
diff --git a/zebra-script/Cargo.toml b/zebra-script/Cargo.toml
index c5cca82a..7f58aa71 100644
--- a/zebra-script/Cargo.toml
+++ b/zebra-script/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "zebra-script"
-version = "1.0.0-alpha.18"
+version = "1.0.0-alpha.19"
 authors = ["Zcash Foundation <zebra@zfnd.org>"]
 license = "MIT OR Apache-2.0"
 edition = "2018"
diff --git a/zebra-state/Cargo.toml b/zebra-state/Cargo.toml
index 068998ac..0c694bf2 100644
--- a/zebra-state/Cargo.toml
+++ b/zebra-state/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "zebra-state"
-version = "1.0.0-alpha.17"
+version = "1.0.0-alpha.18"
 authors = ["Zcash Foundation <zebra@zfnd.org>"]
 license = "MIT OR Apache-2.0"
 edition = "2018"
diff --git a/zebra-test/Cargo.toml b/zebra-test/Cargo.toml
index 013e45a1..bd0e1920 100644
--- a/zebra-test/Cargo.toml
+++ b/zebra-test/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "zebra-test"
-version = "1.0.0-alpha.14"
+version = "1.0.0-alpha.15"
 authors = ["Zcash Foundation <zebra@zfnd.org>"]
 license = "MIT OR Apache-2.0"
 edition = "2018"
diff --git a/zebra-utils/Cargo.toml b/zebra-utils/Cargo.toml
index 6a90a002..ee6d7f40 100644
--- a/zebra-utils/Cargo.toml
+++ b/zebra-utils/Cargo.toml
@@ -2,7 +2,7 @@
 name = "zebra-utils"
 authors = ["Zcash Foundation <zebra@zfnd.org>"]
 license = "MIT OR Apache-2.0"
-version = "1.0.0-alpha.17"
+version = "1.0.0-alpha.18"
 edition = "2018"
 # Prevent accidental publication of this utility crate.
 publish = false
diff --git a/zebrad/Cargo.toml b/zebrad/Cargo.toml
index ec868813..888c2d45 100644
--- a/zebrad/Cargo.toml
+++ b/zebrad/Cargo.toml
@@ -2,7 +2,7 @@
 name = "zebrad"
 authors = ["Zcash Foundation <zebra@zfnd.org>"]
 license = "MIT OR Apache-2.0"
-version = "1.0.0-alpha.17"
+version = "1.0.0-alpha.18"
 edition = "2018"
 repository = "https://github.com/ZcashFoundation/zebra"
 # make `cargo run` use `zebrad` by default