diff --git a/.github/workflows/branch-checks.yml b/.github/workflows/branch-checks.yml
index 5d4a98c61a..15293454c9 100644
--- a/.github/workflows/branch-checks.yml
+++ b/.github/workflows/branch-checks.yml
@@ -153,6 +153,10 @@ jobs:
           cache-bin: "false"
           cmd-format: nix develop .#devShells.${{ matrix.system }}.default -c {0}
 
+      - name: Verify Cargo lockfiles
+        if: matrix.system == 'x86_64-linux'
+        run: tasks/scripts/check-cargo-lockfiles.sh
+
       - name: Format
         run: |
           cargo fmt --all -- --check
@@ -162,10 +166,10 @@ jobs:
 
       - name: Lint
         run: |
-          cargo clippy --workspace --all-targets -- -D warnings
-          cargo clippy --manifest-path e2e/rust/Cargo.toml --all-targets -- -D warnings
-          cargo check --manifest-path examples/governance-interceptor/Cargo.toml --all-targets
-          cargo check --manifest-path examples/supervisor-middleware-content-guard/Cargo.toml --all-targets
+          cargo clippy --locked --workspace --all-targets -- -D warnings
+          cargo clippy --locked --manifest-path e2e/rust/Cargo.toml --all-targets -- -D warnings
+          cargo check --locked --manifest-path examples/governance-interceptor/Cargo.toml --all-targets
+          cargo check --locked --manifest-path examples/supervisor-middleware-content-guard/Cargo.toml --all-targets
 
       - name: Test
         env:
diff --git a/TESTING.md b/TESTING.md
index 14ec3c2055..ccb183f61f 100644
--- a/TESTING.md
+++ b/TESTING.md
@@ -46,6 +46,8 @@ Run Rust tests only:
 mise run test:rust     # cargo test --workspace
 ```
 
+Run `mise run rust:lockfiles:check` to validate every tracked Cargo lockfile against its adjacent manifest. Cargo diagnostics explain whether a failure requires refreshing a lockfile or resolving another problem, such as registry access. To refresh a stale lockfile, run `cargo metadata --format-version 1 --manifest-path path/to/Cargo.toml > /dev/null` with the adjacent manifest, review and commit the lockfile changes, then rerun `mise run pre-commit`.
+
 ## Python Unit Tests
 
 Python unit tests use the `*_test.py` suffix convention (not `test_*` prefix)
diff --git a/tasks/rust.toml b/tasks/rust.toml
index e62e22b3cf..2189da2d53 100644
--- a/tasks/rust.toml
+++ b/tasks/rust.toml
@@ -5,17 +5,22 @@
 
 ["rust:check"]
 description = "Check all Rust crates for errors"
-run = "cargo check --workspace"
+run = "cargo check --locked --workspace"
 run_windows = "powershell -NoProfile -ExecutionPolicy Bypass -File tasks/scripts/windows-msvc.ps1 check native"
 hide = true
 
+["rust:lockfiles:check"]
+description = "Verify all tracked Cargo lockfiles are current"
+run = "tasks/scripts/check-cargo-lockfiles.sh"
+hide = true
+
 ["rust:lint"]
 description = "Lint Rust code with Clippy (deny warnings)"
 run = [
-  "cargo clippy --workspace --all-targets -- -D warnings",
-  "cargo clippy --manifest-path e2e/rust/Cargo.toml --all-targets -- -D warnings",
-  "cargo check --manifest-path examples/governance-interceptor/Cargo.toml --all-targets",
-  "cargo check --manifest-path examples/supervisor-middleware-content-guard/Cargo.toml --all-targets",
+  "cargo clippy --locked --workspace --all-targets -- -D warnings",
+  "cargo clippy --locked --manifest-path e2e/rust/Cargo.toml --all-targets -- -D warnings",
+  "cargo check --locked --manifest-path examples/governance-interceptor/Cargo.toml --all-targets",
+  "cargo check --locked --manifest-path examples/supervisor-middleware-content-guard/Cargo.toml --all-targets",
 ]
 run_windows = "powershell -NoProfile -ExecutionPolicy Bypass -File tasks/scripts/windows-msvc.ps1 lint native"
 hide = true
diff --git a/tasks/scripts/check-cargo-lockfiles.sh b/tasks/scripts/check-cargo-lockfiles.sh
new file mode 100755
index 0000000000..bd74d8d647
--- /dev/null
+++ b/tasks/scripts/check-cargo-lockfiles.sh
@@ -0,0 +1,54 @@
+#!/usr/bin/env bash
+# SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+set -euo pipefail
+
+check_lockfile() {
+  local lockfile="$1"
+  local manifest="${lockfile%Cargo.lock}Cargo.toml"
+
+  if [[ ! -f "$manifest" ]]; then
+    printf 'error: tracked lockfile %s has no adjacent Cargo.toml\n' "$lockfile" >&2
+    return 1
+  fi
+
+  printf 'Checking %s\n' "$lockfile"
+  if ! cargo metadata \
+    --locked \
+    --format-version 1 \
+    --manifest-path "$manifest" \
+    >/dev/null; then
+    printf 'error: validation failed for %s\n' "$lockfile" >&2
+    return 1
+  fi
+}
+
+main() {
+  local lockfile
+  local found=0
+  local failed=0
+
+  cd "$(git rev-parse --show-toplevel)"
+
+  # Policy: every tracked Cargo.lock represents an intentionally reproducible
+  # Cargo workspace and must resolve against its adjacent Cargo.toml. Manifests
+  # that intentionally do not own a lockfile are outside this check.
+  while IFS= read -r -d '' lockfile; do
+    found=1
+    check_lockfile "$lockfile" || failed=1
+  done < <(git ls-files -z -- ':(glob)**/Cargo.lock')
+
+  if [[ "$found" -eq 0 ]]; then
+    echo "error: no tracked Cargo.lock files found" >&2
+    return 1
+  fi
+
+  if [[ "$failed" -ne 0 ]]; then
+    echo "Resolve the reported errors. If a lockfile needs updating, refresh it with Cargo and commit the result." >&2
+  fi
+
+  return "$failed"
+}
+
+main "$@"
diff --git a/tasks/test.toml b/tasks/test.toml
index bb1fa2e9ab..712b91b9a6 100644
--- a/tasks/test.toml
+++ b/tasks/test.toml
@@ -267,4 +267,3 @@ description = "Run GPU e2e against a standalone gateway with the Docker compute
 env = { OPENSHELL_E2E_DOCKER_GPU = "1", OPENSHELL_E2E_DOCKER_TEST = "gpu", OPENSHELL_E2E_DOCKER_FEATURES = "e2e-docker-gpu" }
 depends = ["e2e:conformance:build"]
 run = "OPENSHELL_CONFORMANCE_BIN=\"${OPENSHELL_CONFORMANCE_BIN:-$PWD/target/debug/openshell-conformance}\" e2e/rust/e2e-docker.sh"
-