diff --git a/review-enrichment/src/analyzers/eol-check.ts b/review-enrichment/src/analyzers/eol-check.ts
new file mode 100644
index 0000000000..0968bb0058
--- /dev/null
+++ b/review-enrichment/src/analyzers/eol-check.ts
@@ -0,0 +1,137 @@
+// End-of-life runtime regression analyzer (#1504). Parses runtime/base-image/engine version pins a PR changes
+// (Dockerfile FROM, .nvmrc, go.mod) and checks endoflife.date (free, no key) — flagging a pin onto a release that
+// is already past end-of-support or goes EOL within 90 days. The no-checkout reviewer has no EOL calendar; this does.
+import type { EnrichRequest, EolFinding } from "../types.js";
+
+// Docker image / source → endoflife.date product slug.
+const DOCKER_PRODUCT: Record<string, string> = {
+  node: "nodejs",
+  python: "python",
+  golang: "go",
+  ruby: "ruby",
+  php: "php",
+  debian: "debian",
+  ubuntu: "ubuntu",
+  alpine: "alpine",
+};
+
+interface VersionPin {
+  file: string;
+  product: string;
+  version: string;
+}
+
+// Leading numeric version from a tag/value: "3.8-slim" → "3.8", "18" → "18", "latest" → null.
+function leadingVersion(value: string): string | null {
+  return /^v?(\d+(?:\.\d+)*)/.exec(value.trim())?.[1] ?? null;
+}
+
+function isDockerfile(path: string): boolean {
+  const base = path.split("/").pop() ?? path;
+  return base === "Dockerfile" || /\.dockerfile$/i.test(base);
+}
+
+/** Pull (product, version) pins out of the added lines of changed Dockerfile / .nvmrc / go.mod. Pure. */
+export function extractVersionPins(
+  files: NonNullable<EnrichRequest["files"]>,
+): VersionPin[] {
+  const pins: VersionPin[] = [];
+  for (const file of files) {
+    if (!file.patch) continue;
+    const base = file.path.split("/").pop() ?? file.path;
+    for (const raw of file.patch.split("\n")) {
+      if (raw[0] !== "+" || raw.startsWith("+++")) continue;
+      const line = raw.slice(1).trim();
+      if (isDockerfile(file.path)) {
+        const match =
+          /^FROM\s+(?:--platform=\S+\s+)?([a-z0-9._/-]+):([a-zA-Z0-9._-]+)/i.exec(
+            line,
+          );
+        if (match) {
+          const product =
+            DOCKER_PRODUCT[(match[1]!.split("/").pop() ?? "").toLowerCase()];
+          const version = leadingVersion(match[2]!);
+          if (product && version)
+            pins.push({ file: file.path, product, version });
+        }
+      } else if (base === ".nvmrc") {
+        const version = leadingVersion(line);
+        if (version) pins.push({ file: file.path, product: "nodejs", version });
+      } else if (base === "go.mod") {
+        const match = /^go\s+(\d+\.\d+)/.exec(line);
+        if (match)
+          pins.push({ file: file.path, product: "go", version: match[1]! });
+      }
+    }
+  }
+  return pins;
+}
+
+interface Cycle {
+  cycle: string;
+  eol: string | boolean;
+}
+
+// Match a version to its release cycle — most specific (longest) cycle prefix wins (so "18.17" → "18", "3.8" → "3.8").
+function matchCycle(cycles: Cycle[], version: string): Cycle | undefined {
+  const sorted = [...cycles].sort((a, b) => b.cycle.length - a.cycle.length);
+  return (
+    sorted.find(
+      (c) => version === c.cycle || version.startsWith(c.cycle + "."),
+    ) ?? sorted.find((c) => version.split(".")[0] === c.cycle)
+  );
+}
+
+function eolStatus(
+  eol: string | boolean,
+  now: number,
+): EolFinding["status"] | null {
+  if (eol === false) return null;
+  if (eol === true) return "eol";
+  const eolMs = new Date(eol).getTime();
+  if (!Number.isFinite(eolMs)) return null;
+  if (eolMs < now) return "eol";
+  if (eolMs < now + 90 * 86_400_000) return "soon";
+  return null;
+}
+
+async function fetchCycles(
+  product: string,
+  fetchImpl: typeof fetch,
+): Promise<Cycle[] | null> {
+  const response = await fetchImpl(
+    `https://endoflife.date/api/${product}.json`,
+  );
+  if (!response.ok) return null;
+  const data = (await response.json()) as Cycle[];
+  return Array.isArray(data) ? data : null;
+}
+
+/** Analyzer entrypoint: changed runtime pins → endoflife.date → only the EOL / EOL-soon ones. `now` injectable. */
+export async function scanEol(
+  req: EnrichRequest,
+  fetchImpl: typeof fetch = fetch,
+  now: number = Date.now(),
+): Promise<EolFinding[]> {
+  const findings: EolFinding[] = [];
+  const seen = new Set<string>();
+  for (const pin of extractVersionPins(req.files ?? [])) {
+    const key = `${pin.product}:${pin.version}`;
+    if (seen.has(key)) continue;
+    seen.add(key);
+    const cycles = await fetchCycles(pin.product, fetchImpl);
+    if (!cycles) continue;
+    const cycle = matchCycle(cycles, pin.version);
+    if (!cycle) continue;
+    const status = eolStatus(cycle.eol, now);
+    if (status)
+      findings.push({
+        file: pin.file,
+        product: pin.product,
+        version: pin.version,
+        eol: String(cycle.eol),
+        status,
+      });
+  }
+  return findings;
+}
diff --git a/review-enrichment/src/brief.ts b/review-enrichment/src/brief.ts
index 54eda8355e..75d91b181f 100644
--- a/review-enrichment/src/brief.ts
+++ b/review-enrichment/src/brief.ts
@@ -12,6 +12,7 @@ import { scanSecrets } from "./analyzers/secret-scan.js";
 import { scanLicenses } from "./analyzers/license-check.js";
 import { scanInstallScripts } from "./analyzers/install-scripts.js";
 import { scanActionPins } from "./analyzers/actions-pin.js";
+import { scanEol } from "./analyzers/eol-check.js";
 import { renderBrief } from "./render.js";
 
 type AnalyzerFn = (req: EnrichRequest) => Promise<unknown>;
@@ -23,6 +24,7 @@ const ANALYZERS: Record<keyof BriefFindings, AnalyzerFn> = {
   license: (req) => scanLicenses(req),
   installScript: (req) => scanInstallScripts(req),
   actionPin: (req) => scanActionPins(req),
+  eol: (req) => scanEol(req),
 };
 
 function withTimeout<T>(promise: Promise<T>, ms: number): Promise<T> {
diff --git a/review-enrichment/src/render.ts b/review-enrichment/src/render.ts
index fd46922ed5..993f36f085 100644
--- a/review-enrichment/src/render.ts
+++ b/review-enrichment/src/render.ts
@@ -82,6 +82,17 @@ export function renderBrief(
     }
   }
 
+  const eol = findings.eol ?? [];
+  if (eol.length) {
+    lines.push("### End-of-life runtimes (upgrade before merging)");
+    for (const item of eol) {
+      const label = item.status === "eol" ? "END-OF-LIFE" : "EOL soon";
+      lines.push(
+        `- \`${item.file}\` pins ${item.product} ${item.version} — **${label}** (EOL ${item.eol})`,
+      );
+    }
+  }
+
   if (!lines.length) return { promptSection: "", systemSuffix: "" };
 
   const header =
diff --git a/review-enrichment/src/types.ts b/review-enrichment/src/types.ts
index ff505df4a5..785650f7b0 100644
--- a/review-enrichment/src/types.ts
+++ b/review-enrichment/src/types.ts
@@ -75,6 +75,15 @@ export interface ActionPinFinding {
   ref: string;
 }
 
+/** A runtime/base-image/engine pinned to a release that is past end-of-support (or EOL within 90 days). */
+export interface EolFinding {
+  file: string;
+  product: string;
+  version: string;
+  eol: string;
+  status: "eol" | "soon";
+}
+
 /** Structured analyzer output. Each analyzer fills its own key; more land as analyzers ship (#1477/#1478). */
 export interface BriefFindings {
   dependency?: DependencyFinding[];
@@ -82,6 +91,7 @@ export interface BriefFindings {
   license?: LicenseFinding[];
   actionPin?: ActionPinFinding[];
   installScript?: InstallScriptFinding[];
+  eol?: EolFinding[];
 }
 
 export type AnalyzerStatus = "ok" | "degraded" | "skipped";
diff --git a/review-enrichment/test/enrichment.test.ts b/review-enrichment/test/enrichment.test.ts
index e2606badbd..763bd0aefb 100644
--- a/review-enrichment/test/enrichment.test.ts
+++ b/review-enrichment/test/enrichment.test.ts
@@ -14,6 +14,17 @@ import {
   scanWorkflowPins,
   scanActionPins,
 } from "../dist/analyzers/actions-pin.js";
+import { scanEol, extractVersionPins } from "../dist/analyzers/eol-check.js";
+
+const NOW = new Date("2026-06-26").getTime();
+const eolFetch =
+  (cycles, ok = true) =>
+  async () => ({ ok, json: async () => cycles });
+const dockerfilePatch = (tag) => ({
+  repoFullName: "o/r",
+  prNumber: 1,
+  files: [{ path: "Dockerfile", patch: `@@ -1,0 +1,1 @@\n+FROM node:${tag}` }],
+});
 
 const npmFetch =
   (scripts, time = {}) =>
@@ -469,3 +480,90 @@ test("buildBrief: action-pin analyzer runs (pure, no network)", async () => {
     globalThis.fetch = realFetch;
   }
 });
+
+test("extractVersionPins: Dockerfile FROM + .nvmrc + go.mod; latest skipped", () => {
+  const pins = extractVersionPins([
+    {
+      path: "Dockerfile",
+      patch: "@@ -1,0 +1,2 @@\n+FROM python:3.8-slim\n+FROM node:latest",
+    },
+    { path: ".nvmrc", patch: "@@ -1,0 +1,1 @@\n+v18.17.0" },
+    { path: "go.mod", patch: "@@ -1,0 +1,1 @@\n+go 1.20" },
+  ]);
+  const byProduct = Object.fromEntries(pins.map((p) => [p.product, p]));
+  assert.equal(byProduct.python.version, "3.8");
+  assert.equal(byProduct.nodejs.version, "18.17.0");
+  assert.equal(byProduct.go.version, "1.20");
+  assert.ok(
+    !pins.some((p) => p.product === "nodejs" && p.file === "Dockerfile"),
+  ); // node:latest skipped
+});
+
+test("scanEol: flags EOL + EOL-soon, skips current + fetch-fail (injected now)", async () => {
+  const cycles = [
+    { cycle: "18", eol: "2023-06-01" },
+    { cycle: "20", eol: "2026-07-01" },
+    { cycle: "22", eol: "2027-04-30" },
+    { cycle: "24", eol: false },
+  ];
+  const fetchImpl = eolFetch(cycles);
+  assert.equal(
+    (await scanEol(dockerfilePatch("18"), fetchImpl, NOW))[0].status,
+    "eol",
+  );
+  assert.equal(
+    (await scanEol(dockerfilePatch("20"), fetchImpl, NOW))[0].status,
+    "soon",
+  );
+  assert.equal(
+    (await scanEol(dockerfilePatch("22"), fetchImpl, NOW)).length,
+    0,
+  );
+  assert.equal(
+    (await scanEol(dockerfilePatch("24"), fetchImpl, NOW)).length,
+    0,
+  ); // eol:false
+  assert.equal(
+    (await scanEol(dockerfilePatch("18"), eolFetch([], false), NOW)).length,
+    0,
+  );
+});
+
+test("renderBrief: renders the EOL block", () => {
+  const r = renderBrief({
+    eol: [
+      {
+        file: "Dockerfile",
+        product: "nodejs",
+        version: "18",
+        eol: "2023-06-01",
+        status: "eol",
+      },
+    ],
+  });
+  assert.match(r.promptSection, /End-of-life runtimes/);
+  assert.match(
+    r.promptSection,
+    /pins nodejs 18 — \*\*END-OF-LIFE\*\* \(EOL 2023-06-01\)/,
+  );
+});
+
+test("buildBrief: eol analyzer runs (real now, 2023 cycle is past)", async () => {
+  const realFetch = globalThis.fetch;
+  globalThis.fetch = async (url) =>
+    String(url).includes("endoflife.date")
+      ? { ok: true, json: async () => [{ cycle: "18", eol: "2023-06-01" }] }
+      : { ok: true, json: async () => ({}) };
+  try {
+    const brief = await buildBrief({
+      repoFullName: "o/r",
+      prNumber: 1,
+      files: [{ path: "Dockerfile", patch: "@@ -1,0 +1,1 @@\n+FROM node:18" }],
+    });
+    assert.equal(brief.analyzerStatus.eol, "ok");
+    assert.equal(brief.findings.eol.length, 1);
+    assert.match(brief.promptSection, /End-of-life runtimes/);
+  } finally {
+    globalThis.fetch = realFetch;
+  }
+});