diff --git a/scripts/draft-stable-notes.sh b/scripts/draft-stable-notes.sh
index 1ba75033d7..5bd42e9ba1 100755
--- a/scripts/draft-stable-notes.sh
+++ b/scripts/draft-stable-notes.sh
@@ -70,28 +70,54 @@ if ! git -C "$repo_dir" rev-parse --verify "refs/tags/${beta_tag}" >/dev/null 2>
   release_fail "beta tag ${beta_tag} does not exist. Draft notes are generated from a published beta."
 fi
 source_sha="$(git -C "$repo_dir" rev-parse "${beta_tag}^{commit}")"
+source_short="$(git -C "$repo_dir" rev-parse --short "$source_sha")"
 
 if [ -z "$out_file" ]; then
   out_file="${repo_dir}/releases/beta/v${beta_version}.md"
 fi
 
-# Range start: the newest stable tag reachable from the source commit —
-# not the newest by version, which can sit on a divergent lineage (a
-# stable cut from a candidate branch, or a source that predates it) and
-# would produce an empty or wrong range. Before the first reachable
-# stable, fall back to the nearest beta tag strictly before the source;
-# with no marker at all, cover the source commit's full history.
-range_start="$(git -C "$repo_dir" describe --tags --match 'v[0-9]*' --abbrev=0 "$source_sha" 2>/dev/null || true)"
-range_label="$range_start"
+# Range start: walk stable tags newest-first and take the first whose
+# merge-base with the source is a proper ancestor of the source. A stable
+# cut from a candidate branch is not itself an ancestor of master, but
+# its merge-base with the source is the promoted source commit — exactly
+# the point the shipped stable's content diverges from. A stable that
+# already contains the source (promoting an older commit) is skipped so
+# the range never collapses to empty. Before the first stable, fall back
+# to the nearest beta tag strictly before the source; with no marker at
+# all, cover the source commit's full history.
+range_start=""
+range_label=""
+range_cmd_start=""
+while IFS= read -r stable_tag; do
+  [ -n "$stable_tag" ] || continue
+  mb="$(git -C "$repo_dir" merge-base "$stable_tag" "$source_sha" 2>/dev/null || true)"
+  [ -n "$mb" ] || continue
+  if [ "$mb" != "$source_sha" ]; then
+    range_start="$mb"
+    if [ "$mb" = "$(git -C "$repo_dir" rev-parse "${stable_tag}^{commit}")" ]; then
+      range_label="$stable_tag"
+      range_cmd_start="$stable_tag"
+    else
+      # rev-parse --short picks an abbreviation that is unambiguous in
+      # this repository, unlike a fixed nine-character truncation.
+      mb_short="$(git -C "$repo_dir" rev-parse --short "$mb")"
+      range_label="${stable_tag} (merge-base ${mb_short})"
+      range_cmd_start="$mb_short"
+    fi
+    break
+  fi
+done < <(git -C "$repo_dir" tag -l 'v[0-9]*' --sort=-v:refname)
 if [ -z "$range_start" ]; then
   range_start="$(git -C "$repo_dir" describe --tags --match 'beta/v*' --abbrev=0 "${source_sha}^" 2>/dev/null || true)"
   range_label="$range_start"
+  range_cmd_start="$range_start"
 fi
 if [ -n "$range_start" ]; then
   range="${range_start}..${source_sha}"
 else
   range="$source_sha"
   range_label="the beginning of history"
+  range_cmd_start="the beginning of history"
   release_info "No stable or prior beta tag found; drafting from full history."
 fi
 
@@ -114,7 +140,7 @@ conventional='^(feat|fix)(\([^)]*\))?!?: '
 mkdir -p "$(dirname "$out_file")"
 {
   printf '# Paperclip stable draft — from beta %s\n\n' "$beta_version"
-  printf '> Auto-generated at beta publish from `git log %s..%s`.\n' "${range_label}" "${source_sha:0:9}"
+  printf '> Auto-generated at beta publish from `git log %s..%s` (baseline: %s).\n' "${range_cmd_start}" "${source_short}" "${range_label}"
   printf '> Edit freely during the soak: rewrite for release-notes voice,\n'
   printf '> fold noise, and call out anything a self-hoster must act on.\n'
   printf '> The stable promotion reads this file from master and publishes\n'
diff --git a/scripts/draft-stable-notes.test.mjs b/scripts/draft-stable-notes.test.mjs
index c5bb01dfc0..53479a8773 100644
--- a/scripts/draft-stable-notes.test.mjs
+++ b/scripts/draft-stable-notes.test.mjs
@@ -79,6 +79,26 @@ test("uses the nearest ancestor stable tag, not the newest by version", () => {
   assert.doesNotMatch(body, /new work/);
 });
 
+test("starts from the merge-base when the last stable was cut from a candidate branch", () => {
+  const dir = makeFixtureRepo();
+  commit(dir, "feat: shipped in the stable (#1)");
+  git(dir, "checkout", "-q", "-b", "candidate");
+  commit(dir, "docs: release notes only (#2)");
+  git(dir, "tag", "v2026.200.0");
+  git(dir, "checkout", "-q", "master");
+  commit(dir, "feat: next-release work (#3)");
+  git(dir, "tag", "beta/v2026.201.0-beta.0");
+
+  // The stable tag sits on the unmerged candidate branch, so it is not an
+  // ancestor of the beta source. The range must start at its merge-base
+  // with the source (the promoted commit), not fall back past it.
+  const { body } = runDraft(dir, "2026.201.0-beta.0");
+
+  assert.match(body, /- feat: next-release work \(#3\)/);
+  assert.doesNotMatch(body, /shipped in the stable/);
+  assert.doesNotMatch(body, /release notes only/);
+});
+
 test("falls back to the previous beta tag when no stable tag exists", () => {
   const dir = makeFixtureRepo();
   commit(dir, "feat: first-train work (#1)");