diff --git a/.github/workflows/publish-simplex-desktop.yml b/.github/workflows/publish-simplex-desktop.yml
index 48bd03194f..d452af1bbc 100644
--- a/.github/workflows/publish-simplex-desktop.yml
+++ b/.github/workflows/publish-simplex-desktop.yml
@@ -58,7 +58,7 @@ jobs:
       - name: Setup Node.js
         uses: actions/setup-node@v4
         with:
-          node-version: "24.19.0"
+          node-version: "24.22.1"
 
       - name: Setup pnpm
         uses: pnpm/action-setup@v4
@@ -161,7 +161,7 @@ jobs:
       - name: Setup Node.js
         uses: actions/setup-node@v4
         with:
-          node-version: "24.19.0"
+          node-version: "24.22.1"
 
       - name: Setup pnpm
         uses: pnpm/action-setup@v4
@@ -368,7 +368,7 @@ jobs:
       - name: Setup Node.js
         uses: actions/setup-node@v4
         with:
-          node-version: "24.19.0"
+          node-version: "24.22.1"
 
       - name: Setup pnpm
         uses: pnpm/action-setup@v4
diff --git a/.github/workflows/test-simplex-desktop.yml b/.github/workflows/test-simplex-desktop.yml
index f1384e6e34..f1bb93322d 100644
--- a/.github/workflows/test-simplex-desktop.yml
+++ b/.github/workflows/test-simplex-desktop.yml
@@ -80,14 +80,14 @@ jobs:
 
             - name: Execute staged Node on Unix
               if: runner.os != 'Windows'
-              run: test "$(packages/simplex-desktop/resources/node/${{ matrix.target }}/node --version)" = "v24.19.0"
+              run: test "$(packages/simplex-desktop/resources/node/${{ matrix.target }}/node --version)" = "v24.22.1"
 
             - name: Execute staged Node on Windows
               if: runner.os == 'Windows'
               shell: pwsh
               run: |
                   $version = & "packages/simplex-desktop/resources/node/win32-x64/node.exe" --version
-                  if ($version -ne "v24.19.0") { throw "Expected v24.19.0, got $version" }
+                  if ($version -ne "v24.22.1") { throw "Expected v24.22.1, got $version" }
 
     desktop-e2e-artifacts:
         name: Build Simplex desktop E2E artifacts
diff --git a/docs/content/developers/evm/simplex/installation.mdx b/docs/content/developers/evm/simplex/installation.mdx
index ae9ca64c4f..c1591c18a0 100644
--- a/docs/content/developers/evm/simplex/installation.mdx
+++ b/docs/content/developers/evm/simplex/installation.mdx
@@ -93,7 +93,7 @@ simplex
 ```
 
 The scope matters: the unscoped `simplex` package on npm is unrelated. The installed command is still
-`simplex`. A global install needs Node.js 22.16 or newer; the desktop and Docker distributions bundle
+`simplex`. A global install needs Node.js 22.23.4+, 24.22.1+ or 26.12.1+; the desktop and Docker distributions bundle
 their own runtime.
 
 ## Building a config file
diff --git a/docs/content/developers/sdk/api/simplex.mdx b/docs/content/developers/sdk/api/simplex.mdx
index b64039c37c..cd24e483a9 100644
--- a/docs/content/developers/sdk/api/simplex.mdx
+++ b/docs/content/developers/sdk/api/simplex.mdx
@@ -878,8 +878,8 @@ it is.
 directory written by the binary is picked up unchanged. Limit orders and operator state ride in
 `bids.db` beside the bids, and implements `patch`; a `runtime-state.json` from an earlier version is imported once
 and then removed. It is built on Node's
-built-in `node:sqlite`, so there is no native module to install or compile — which is why the
-package requires Node 22.16 or newer.
+built-in `node:sqlite`, so there is no native module to install or compile. The package requires
+Node 22.23.4+, 24.22.1+ or 26.12.1+.
 
 **Example — a custom backend:**
 
diff --git a/docs/content/developers/sdk/simplex.mdx b/docs/content/developers/sdk/simplex.mdx
index 3115e68823..4df7db1630 100644
--- a/docs/content/developers/sdk/simplex.mdx
+++ b/docs/content/developers/sdk/simplex.mdx
@@ -19,7 +19,7 @@ less work.
 npm install @hyperbridge/simplex
 ```
 
-Node.js 22.16 or later. The package ships ESM and CJS builds with bundled types.
+Node.js 22.23.4+, 24.22.1+ or 26.12.1+. The package ships ESM and CJS builds with bundled types.
 
 ## Starting a solver
 
@@ -254,7 +254,7 @@ that is only reclaimable by retracting it, and the retraction sweep finds what t
 querying the bid store. Lose those records and you leak deposits.
 
 The bundled SQLite store is a separate entry point. It runs on Node's built-in `node:sqlite`, so
-there is no native module to install or compile — the package just needs Node 22.16 or newer:
+there is no native module to install or compile — the package just needs Node 22.23.4+, 24.22.1+ or 26.12.1+:
 
 ```ts lineNumbers
 import { SqliteDataStore } from "@hyperbridge/simplex/sqlite"
diff --git a/sdk/packages/simplex-desktop/README.md b/sdk/packages/simplex-desktop/README.md
index 1fada40825..d00d35bcf0 100644
--- a/sdk/packages/simplex-desktop/README.md
+++ b/sdk/packages/simplex-desktop/README.md
@@ -238,7 +238,7 @@ without a separate trusted network boundary.
 ## Runtime resources
 
 The staging script follows Node's binary-verification procedure: it verifies the signed
-`SHASUMS256.txt.asc` with the pinned release key, verifies the selected Node 24.19.0 archive checksum,
+`SHASUMS256.txt.asc` with the pinned release key, verifies the selected Node 24.22.1 archive checksum,
 and installs only `node` or `node.exe`. `darwin-universal` verifies both macOS slices independently
 before merging them with `lipo`.
 
diff --git a/sdk/packages/simplex-desktop/package.json b/sdk/packages/simplex-desktop/package.json
index 360ea19a13..39cebc4973 100644
--- a/sdk/packages/simplex-desktop/package.json
+++ b/sdk/packages/simplex-desktop/package.json
@@ -1,7 +1,7 @@
 {
 	"name": "@hyperbridge/simplex-desktop",
 	"productName": "Simplex",
-	"version": "0.18.3",
+	"version": "0.18.4",
 	"private": true,
 	"description": "Native desktop shell for the Simplex intent solver",
 	"author": "Polytope Labs <hello@polytope.technology>",
diff --git a/sdk/packages/simplex-desktop/scripts/stage-node.mjs b/sdk/packages/simplex-desktop/scripts/stage-node.mjs
index 2cf4740c99..890aaeec36 100644
--- a/sdk/packages/simplex-desktop/scripts/stage-node.mjs
+++ b/sdk/packages/simplex-desktop/scripts/stage-node.mjs
@@ -9,7 +9,7 @@ import { pipeline } from "node:stream/promises"
 import * as openpgp from "openpgp"
 import * as tar from "tar"
 
-export const NODE_VERSION = "24.19.0"
+export const NODE_VERSION = "24.22.1"
 export const NODE_BASE_URL = `https://nodejs.org/dist/v${NODE_VERSION}`
 export const NODE_RELEASE_KEY_FINGERPRINT = "5BE8A3F6C8A5C01D106C0AD820B1A390B168D356"
 export const TARGETS = ["darwin-arm64", "darwin-x64", "darwin-universal", "linux-arm64", "linux-x64", "win32-x64"]
diff --git a/sdk/packages/simplex/README.md b/sdk/packages/simplex/README.md
index d30e785b2f..859b10f42a 100644
--- a/sdk/packages/simplex/README.md
+++ b/sdk/packages/simplex/README.md
@@ -22,7 +22,7 @@ Embed it in your own Node service, or run it as a ready-made app:
 npm install @hyperbridge/simplex
 ```
 
-Requires Node.js 22.16 or later.
+Requires Node.js 22.23.4+, 24.22.1+ or 26.12.1+.
 
 ## Quick start
 
diff --git a/sdk/packages/simplex/docs/ai/changelog/2026-10-23-node-runtime-node2shell-fix.md b/sdk/packages/simplex/docs/ai/changelog/2026-10-23-node-runtime-node2shell-fix.md
new file mode 100644
index 0000000000..98577ea619
--- /dev/null
+++ b/sdk/packages/simplex/docs/ai/changelog/2026-10-23-node-runtime-node2shell-fix.md
@@ -0,0 +1,27 @@
+# 2026-10-23 — Simplex runs on Node 24.22.1, and requires a Node with the Node2Shell fix
+
+CVE-2026-111497 (Node2Shell) is an out-of-bounds write in the Brotli decoder bundled with Node. Any
+Brotli data the process decompresses can trigger it, and that includes `fetch()` responses with
+`Content-Encoding: br`. Simplex fetches from RPCs, the orderbook, the indexer and bundlers. A malicious
+or compromised endpoint could send a crafted response and run code in the solver.
+
+Remote access does not reach the decoder. The embedded SSH server only negotiates `zlib@openssh.com`
+compression, and `UiServer` reads request bodies as raw bytes without decoding them. The exposure is
+the runtime.
+
+## Runtimes
+
+- The Docker image's builder and runtime stages are on `node:24.22.1` and `node:24.22.1-slim`.
+- The desktop app stages Node 24.22.1 (`NODE_VERSION` in `simplex-desktop/scripts/stage-node.mjs`).
+  The release is signed by the same key the script already pins.
+- The desktop release workflow packages on Node 24.22.1, and the staging check expects `v24.22.1`.
+
+## `engines.node`
+
+`engines.node` is `^22.23.4 || ^24.22.1 || >=26.12.1`: the first patched release on each supported
+line. Node 23 and 25 are end of life and never got the fix, so they are no longer in range. The
+`node:sqlite` floor (22.16.0) is still the oldest version the store can run on. `engines` is only
+advisory, so npm and pnpm warn on an older Node rather than refuse to install.
+
+Electron has no release with the fix yet. The packaged solver runs on the staged Node, not
+Electron's, so this does not change what the solver is exposed to.
diff --git a/sdk/packages/simplex/docs/ai/decisions/2026-09-09-engines-node-floor-is-22-16-0-not-22-13-0-or-24-1236.md b/sdk/packages/simplex/docs/ai/decisions/2026-09-09-engines-node-floor-is-22-16-0-not-22-13-0-or-24-1236.md
index be60cc4cf7..589f2b9aca 100644
--- a/sdk/packages/simplex/docs/ai/decisions/2026-09-09-engines-node-floor-is-22-16-0-not-22-13-0-or-24-1236.md
+++ b/sdk/packages/simplex/docs/ai/decisions/2026-09-09-engines-node-floor-is-22-16-0-not-22-13-0-or-24-1236.md
@@ -3,6 +3,11 @@
 Decided: `>=22.16.0`. That is the first release carrying *every* `node:sqlite` API this store
 calls, which is a stricter bar than the first release where the module is unflagged.
 
+Since 2026-10-23 the declared range is higher: `^22.23.4 || ^24.22.1 || >=26.12.1`, the first
+release on each line with the Node2Shell fix (see
+`changelog/2026-10-23-node-runtime-node2shell-fix.md`). The `node:sqlite` reasoning below still
+sets the oldest version the store itself can run on.
+
 The two dates differ. `node:sqlite` stopped needing `--experimental-sqlite` in v23.4.0 and
 v22.13.0. But `database.isTransaction`, which `attachOrder`'s rollback branch reads, was added in
 v24.0.0 and v22.16.0; `database.isOpen`, which `close()` reads, in v23.11.0 and v22.15.0. So
diff --git a/sdk/packages/simplex/package.json b/sdk/packages/simplex/package.json
index 6814a0e2e9..3f1f0786a3 100644
--- a/sdk/packages/simplex/package.json
+++ b/sdk/packages/simplex/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "@hyperbridge/simplex",
-	"version": "0.18.3",
+	"version": "0.18.4",
 	"license": "Apache-2.0",
 	"description": "Automated intent filler for the Hyperbridge IntentGateway — run it as a binary or embed it as a library",
 	"main": "dist/index.js",
@@ -114,7 +114,7 @@
 		"access": "public"
 	},
 	"engines": {
-		"node": ">=22.16.0"
+		"node": "^22.23.4 || ^24.22.1 || >=26.12.1"
 	},
 	"dependencies": {
 		"@base-ui/react": "^1.8.0",
diff --git a/sdk/packages/simplex/scripts/Dockerfile b/sdk/packages/simplex/scripts/Dockerfile
index 32ddf72515..21cb61843e 100644
--- a/sdk/packages/simplex/scripts/Dockerfile
+++ b/sdk/packages/simplex/scripts/Dockerfile
@@ -16,7 +16,7 @@
 # ---------------------------------------------------------------------------
 # Builder — installs the toolchain, compiles protos, bundles the CLI and web UI.
 # ---------------------------------------------------------------------------
-FROM node:24.19.0 AS builder
+FROM node:24.22.1 AS builder
 
 # protoc is needed by packages/simplex/scripts/build.sh. There is deliberately no python3,
 # make or g++ here: nothing in the tree compiles any more, so node-gyp has nothing to fall
@@ -52,7 +52,7 @@ RUN cd packages/simplex && pnpm build
 # Runtime — slim base, no compiler toolchain. Keeps the pull small on Docker Desktop
 # hosts, where every layer lands inside the Linux VM's disk image.
 # ---------------------------------------------------------------------------
-FROM node:24.19.0-slim AS runtime
+FROM node:24.22.1-slim AS runtime
 
 # Create non-root user
 RUN groupadd -g 1001 simplex && \
diff --git a/sdk/packages/simplex/src/data/sqlite/index.ts b/sdk/packages/simplex/src/data/sqlite/index.ts
index 5a876ccfc3..d175a81695 100644
--- a/sdk/packages/simplex/src/data/sqlite/index.ts
+++ b/sdk/packages/simplex/src/data/sqlite/index.ts
@@ -31,8 +31,9 @@ export { SqliteStateStore } from "./state"
  * Set through the PRAGMA rather than `DatabaseSync`'s `timeout` option on purpose.
  * That option only exists in Node >=22.18 and >=24 (`@types/node` says 22.16, which
  * is wrong — the version table on nodejs.org is authoritative), so it is silently
- * ignored on 22.16, 22.17 and the whole 23 line, all of which `engines.node`
- * admits. The PRAGMA is plain SQLite and works wherever `node:sqlite` does.
+ * ignored on 22.16, 22.17 and the whole 23 line. `engines.node` no longer admits
+ * those, but it is only advisory. The PRAGMA is plain SQLite and works wherever
+ * `node:sqlite` does.
  */
 const BUSY_TIMEOUT_MS = 5_000