@@ -24,26 +24,31 @@ jobs:
         os:
         - 'ubuntu-latest'
         python:
-          - 3.15-dev
-          - 3.14
-          - 3.13
+          - '3.15'
+          - '3.14'
+          - '3.13'
+          - pypy-3.12
           - pypy-3.11
           - graalpy-25.0
     steps:
-      - uses: actions/checkout@v6
-      - uses: actions/setup-python@v6
+      - uses: actions/checkout@v7
+      - uses: actions/setup-python@v7
         with:
           python-version: ${{ matrix.python }}
+          # Lets '3.15' resolve to the newest release candidate until
+          # 3.15.0 final lands in setup-python, then to the final.
+          allow-prereleases: true
       - run: python -m simplejson.tests._cibw_runner .
 
   test_prerelease:
-    name: Tests with C speedups on Python 3.15-dev
+    name: Tests with C speedups on Python 3.15
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
-      - uses: actions/setup-python@v6
+      - uses: actions/checkout@v7
+      - uses: actions/setup-python@v7
         with:
-          python-version: '3.15-dev'
+          python-version: '3.15'
+          allow-prereleases: true
       - name: Build extension
         run: |
           python -m pip install --upgrade pip setuptools wheel
@@ -61,21 +66,28 @@ jobs:
         run: python -m simplejson.tests._cibw_runner .
 
   test_free_threading:
-    name: Tests with free-threading on Python 3.14t
+    name: Tests with free-threading on Python ${{ matrix.python }}
     runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        python:
+          - '3.14t'
+          - '3.15t'
     steps:
-      - uses: actions/checkout@v6
-      - uses: actions/setup-python@v6
+      - uses: actions/checkout@v7
+      - uses: actions/setup-python@v7
         with:
-          python-version: '3.14t'
+          python-version: ${{ matrix.python }}
+          allow-prereleases: true
       - name: Verify Python is a free-threaded build
         run: |
           python -c "
           import sys, sysconfig
           gil_disabled = sysconfig.get_config_var('Py_GIL_DISABLED')
           assert gil_disabled == 1, (
               'Python is not a free-threaded build '
-              '(Py_GIL_DISABLED={!r}); setup-python did not install 3.14t.'
+              '(Py_GIL_DISABLED={!r}); setup-python did not install ${{ matrix.python }}.'
               .format(gil_disabled))
           print('OK: Py_GIL_DISABLED=1, sys.version=' + sys.version)
           "
@@ -108,13 +120,13 @@ jobs:
           - "free-threaded"
         include:
           - variant: "standard"
-            uv_python: "cpython-3.14.4+debug"
+            uv_python: "cpython-3.14.8+debug"
           - variant: "free-threaded"
-            uv_python: "cpython-3.14.4+freethreaded+debug"
+            uv_python: "cpython-3.14.8+freethreaded+debug"
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
       - name: Install uv
-        uses: astral-sh/setup-uv@v8.0.0
+        uses: astral-sh/setup-uv@v10.2.0
       - name: Install Python via python-build-standalone (${{ matrix.uv_python }})
         run: |
           uv python install ${{ matrix.uv_python }}
@@ -157,16 +169,16 @@ jobs:
         run: PYTHON_GIL=0 .venv/bin/python -m simplejson.tests._cibw_runner .
 
   test_tsan:
-    name: TSan stress (CPython v3.14.0 free-threaded)
+    name: TSan stress (CPython v3.14.8 free-threaded)
     runs-on: ubuntu-latest
     env:
       # Keep in sync with the name above. Pinned so the cache key is stable;
       # bump when moving to a newer CPython (cache is keyed on this + clang
       # version + script hash).
-      CPYTHON_REF: v3.14.0
+      CPYTHON_REF: v3.14.8
       TSAN_ROOT: /home/runner/.cache/py-tsan-ft
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
       - name: Install build deps
         run: |
           sudo apt-get update
@@ -181,7 +193,7 @@ jobs:
           echo "version=${version}" >> "$GITHUB_OUTPUT"
       - name: Restore TSan CPython build
         id: cache
-        uses: actions/cache/restore@v5
+        uses: actions/cache/restore@v6
         with:
           path: ${{ env.TSAN_ROOT }}
           key: tsan-cpython-${{ env.CPYTHON_REF }}-${{ runner.os }}-clang${{ steps.clang.outputs.version }}-${{ hashFiles('scripts/run_tsan_stress.sh') }}
@@ -195,7 +207,7 @@ jobs:
         # Skip save on cache hit (nothing new) or if the build itself failed
         # (would cache a broken install).
         if: always() && steps.cache.outputs.cache-hit != 'true' && steps.build.outcome == 'success'
-        uses: actions/cache/save@v5
+        uses: actions/cache/save@v6
         with:
           path: ${{ env.TSAN_ROOT }}
           key: ${{ steps.cache.outputs.cache-primary-key }}
@@ -223,7 +235,7 @@ jobs:
             arch: x86
             msvc_arch: x86
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
 
       - name: Activate MSVC toolchain (Windows only)
         if: runner.os == 'Windows'
@@ -283,7 +295,7 @@ jobs:
             arch: "x86_64 universal2 arm64"
 
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
 
       - name: Set up QEMU
         if: runner.os == 'Linux'
@@ -292,7 +304,7 @@ jobs:
           platforms: all
 
       - name: Build wheels
-        uses: pypa/cibuildwheel@v4.2.0
+        uses: pypa/cibuildwheel@v4.2.1
         env:
           CIBW_TEST_COMMAND: >-
             python -m simplejson.tests._cibw_runner "{project}"
@@ -311,17 +323,17 @@ jobs:
     name: Build Pyodide wheel (wasm32)
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
 
-      - uses: actions/setup-python@v6
+      - uses: actions/setup-python@v7
         name: Install Python
         with:
           # Host Python for cibuildwheel; Pyodide targets are selected
           # by cibuildwheel independently (currently cp312 + cp313).
           python-version: '3.14'
 
       - name: Build Pyodide wheel with C speedups
-        uses: pypa/cibuildwheel@v4.2.0
+        uses: pypa/cibuildwheel@v4.2.1
         env:
           CIBW_PLATFORM: pyodide
           CIBW_TEST_COMMAND: >-
@@ -337,9 +349,9 @@ jobs:
     name: Build source distribution
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
 
-      - uses: actions/setup-python@v6
+      - uses: actions/setup-python@v7
         name: Install Python
         with:
           python-version: '3.14'
@@ -373,9 +385,9 @@ jobs:
     name: Test PEP 517 build (pyproject.toml)
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
 
-      - uses: actions/setup-python@v6
+      - uses: actions/setup-python@v7
         name: Install Python
         with:
           python-version: '3.14'
 
@@ -14,25 +14,25 @@ variants (including debug and free-threaded debug) in under 10 seconds:
 
 ```bash
 # Regular release (same thing setup-python installs in CI)
-uv python install cpython-3.14.4
+uv python install cpython-3.14.8
 
 # Debug build — exposes sys.gettotalrefcount, Py_DECREF asserts,
 # and the internal consistency checks release builds skip. This is
 # the variant that caught the -1LL << n UB bug.
-uv python install cpython-3.14.4+debug
+uv python install cpython-3.14.8+debug
 
 # Free-threaded + debug — highest-value single variant for this PR.
 # Stacks refcount asserts, GIL-disabled scheduling, and the
 # specializer in one interpreter.
-uv python install cpython-3.14.4+freethreaded+debug
+uv python install cpython-3.14.8+freethreaded+debug
 ```
 
 Each installed Python is a self-contained directory under
 `~/.local/share/uv/python/`. Make a venv and install `setuptools`+
 `wheel` with `uv pip`:
 
 ```bash
-uv venv --python cpython-3.14.4+debug /tmp/debug-venv
+uv venv --python cpython-3.14.8+debug /tmp/debug-venv
 uv pip install --python /tmp/debug-venv/bin/python setuptools wheel
 rm -f simplejson/_speedups*.so
 REQUIRE_SPEEDUPS=1 /tmp/debug-venv/bin/python setup.py build_ext -i
@@ -68,7 +68,7 @@ page only sees the failure *annotations*, not the actual step output.
 When you see an annotation like `pip wheel ... failed with code 1`
 and no detail:
 
-1. Reproduce locally across `python3.10`..`python3.14.4` and both
+1. Reproduce locally across `python3.10`..`python3.14.8` and both
    free-threaded + debug via uv. 90% of real failures reproduce.
 2. Check if the run is **stale** — compare the run's head SHA
    against the branch head. `mcp__github__list_commits` for the
@@ -83,8 +83,8 @@ and no detail:
 
 Two cibuildwheel versions run in one job:
 
-- **Main `Build wheels` step** uses `pypa/cibuildwheel@v3.4.1` (Py3).
-  In v3.x **PyPy is disabled by default**; `CIBW_SKIP: "pp*"` *errors*
+- **Main `Build wheels` step** uses `pypa/cibuildwheel@v4.2.1` (Py3).
+  In v3.x and later **PyPy is disabled by default**; `CIBW_SKIP: "pp*"` *errors*
   with `Invalid skip selector: 'pp*'. This selector matches a group
   that wasn't enabled.` Do not set it.
 - **`Build Python 2.7 wheels` step** uses `pypa/cibuildwheel@v1.12.0`.
@@ -137,7 +137,7 @@ Asserting on the total delta will flake.
 Earlier Python versions don't. A local release build with `-Werror`
 will pass on 3.11/3.12/3.13 and fail on 3.14 if you introduce any
 unreachable code on a hot path. Always spot-check with
-`cpython-3.14.4` specifically when doing C refactors.
+`cpython-3.14.8` specifically when doing C refactors.
 
 ## `_speedups_scan.h` is included **twice**
 
 
@@ -1,3 +1,26 @@
+Version 4.2.0 released 2026-10-02
+
+* Start building wheels for Python 3.15 and drop Python 3.8 support
+  via upgrade to cibuildwheel v4.2.0
+  https://github.com/simplejson/simplejson/pull/385
+* Build and test riscv64 Linux wheels on native RISE runners
+  https://github.com/simplejson/simplejson/pull/389
+* The C scanner now reports the same error message as the pure Python
+  decoder for an invalid first key in an object
+  https://github.com/simplejson/simplejson/pull/388
+* ``int_as_string_bitcount`` now supports thresholds of 64 bits and above
+  (including 128-bit integers) in both the C and pure Python encoders;
+  the C encoder previously rejected them
+  https://github.com/simplejson/simplejson/pull/387
+* Circular references introduced through ``for_json()`` or ``_asdict()``
+  now raise ``ValueError("Circular reference detected")`` instead of
+  recursing without bound
+  https://github.com/simplejson/simplejson/pull/390
+* CI now tests Python 3.15 (including free-threaded 3.15t), PyPy 3.12,
+  CPython 3.14.8 debug builds, and uses current GitHub Actions and
+  cibuildwheel v4.2.1
+  https://github.com/simplejson/simplejson/pull/386
+
 Version 4.1.2 released 2026-08-26
 
 * Fix control character error position when content precedes the control char
 
@@ -42,9 +42,9 @@
 # other places throughout the built documents.
 #
 # The short X.Y version.
-version = '4.1'
+version = '4.2'
 # The full version, including alpha/beta/rc tags.
-release = '4.1.2'
+release = '4.2.0'
 
 # There are two options for replacing |today|: either, you set today to some
 # non-false value, then it is used:
 
@@ -12,7 +12,7 @@
 
 set -euo pipefail
 
-: "${CPYTHON_REF:=v3.14.0}"
+: "${CPYTHON_REF:=v3.14.8}"
 : "${CPYTHON_REPO:=https://github.com/python/cpython.git}"
 : "${TSAN_ROOT:=${HOME}/.cache/py-tsan-ft}"
 : "${TSAN_OPTIONS:=halt_on_error=0 second_deadlock_stack=1 history_size=7 handle_segv=0}"
 
@@ -12,7 +12,7 @@
 
 IS_PYPY = hasattr(sys, 'pypy_translation_info')
 IS_GRAALPY = getattr(getattr(sys, "implementation", None), "name", None) == "graalpy"
-VERSION = '4.1.2'
+VERSION = '4.2.0'
 DESCRIPTION = "Simple, fast, extensible JSON encoder/decoder for Python"
 
 with open('README.rst', 'r') as f:
 
@@ -118,7 +118,7 @@
 
 """
 from __future__ import absolute_import
-__version__ = '4.1.2'
+__version__ = '4.2.0'
 __all__ = [
     'dump', 'dumps', 'load', 'loads',
     'JSONDecoder', 'JSONDecodeError', 'JSONEncoder',