diff --git a/.github/scripts/close_fixed_fuzzer_issues.py b/.github/scripts/close_fixed_fuzzer_issues.py
new file mode 100755
index 00000000000..ab637e725de
--- /dev/null
+++ b/.github/scripts/close_fixed_fuzzer_issues.py
@@ -0,0 +1,350 @@
+#!/usr/bin/env python3
+"""Retest open fuzzer issues and close those whose crashes no longer reproduce.
+
+Usage:
+    python3 close_fixed_fuzzer_issues.py --target file_io
+    python3 close_fixed_fuzzer_issues.py --target file_io --dry-run
+"""
+
+from __future__ import annotations
+
+import argparse
+import json
+import os
+import re
+import subprocess
+import sys
+import tempfile
+from dataclasses import dataclass
+
+CLEANUP_MARKER = "Auto-checked by weekly fuzzer issue cleanup"
+
+
+@dataclass
+class FuzzerIssue:
+    number: int
+    title: str
+    target: str
+    crash_file: str
+    artifact_url: str
+    body: str
+
+
+def run(cmd: list[str], **kwargs) -> subprocess.CompletedProcess:
+    """Run a command, printing it for visibility."""
+    print(f"  $ {' '.join(cmd)}", flush=True)
+    return subprocess.run(cmd, **kwargs)
+
+
+def fetch_open_fuzzer_issues(repo: str) -> list[dict]:
+    """Fetch all open issues with the 'fuzzer' label."""
+    result = run(
+        [
+            "gh",
+            "issue",
+            "list",
+            "--repo",
+            repo,
+            "--label",
+            "fuzzer",
+            "--state",
+            "open",
+            "--json",
+            "number,title,body,url",
+            "--limit",
+            "200",
+        ],
+        capture_output=True,
+        text=True,
+    )
+    if result.returncode != 0:
+        print(f"ERROR: Failed to fetch issues: {result.stderr}", file=sys.stderr)
+        sys.exit(1)
+    return json.loads(result.stdout)
+
+
+def parse_issue(issue: dict) -> FuzzerIssue | None:
+    """Extract target, crash file, and artifact URL from an issue body."""
+    body = issue.get("body", "")
+
+    target_match = re.search(r"\*\*Target\*\*:\s*`([^`]+)`", body)
+    crash_file_match = re.search(r"\*\*Crash File\*\*:\s*`([^`]+)`", body)
+    artifact_url_match = re.search(r"\*\*Crash Artifact\*\*:\s*(https://\S+)", body)
+
+    if not target_match or not crash_file_match:
+        return None
+
+    return FuzzerIssue(
+        number=issue["number"],
+        title=issue["title"],
+        target=target_match.group(1),
+        crash_file=crash_file_match.group(1),
+        artifact_url=artifact_url_match.group(1) if artifact_url_match else "",
+        body=body,
+    )
+
+
+def extract_run_id(artifact_url: str) -> str | None:
+    """Extract the workflow run ID from an artifact URL like .../runs/12345/..."""
+    match = re.search(r"runs/(\d+)", artifact_url)
+    return match.group(1) if match else None
+
+
+def has_cleanup_comment(repo: str, issue_number: int) -> bool:
+    """Check if the issue already has an 'Artifact Unavailable' cleanup comment."""
+    result = run(
+        [
+            "gh",
+            "api",
+            f"repos/{repo}/issues/{issue_number}/comments",
+            "--jq",
+            f'[.[] | select(.body | contains("{CLEANUP_MARKER}"))] | length',
+        ],
+        capture_output=True,
+        text=True,
+    )
+    if result.returncode != 0:
+        return False
+    try:
+        return int(result.stdout.strip()) > 0
+    except ValueError:
+        return False
+
+
+def close_artifact_unavailable(repo: str, issue_number: int, dry_run: bool) -> None:
+    """Comment that the crash artifact is no longer available and close the issue."""
+    body = (
+        f"## Artifact Unavailable\n\n"
+        f"The crash artifact for this issue is no longer available "
+        f"(artifacts expire after 30 days). The crash can no longer be "
+        f"automatically retested.\n\n"
+        f"If this issue is still relevant, please reproduce manually and "
+        f"re-open this issue.\n\n"
+        f"---\n*{CLEANUP_MARKER}*"
+    )
+    if dry_run:
+        print(f"  [dry-run] Would close #{issue_number} as artifact unavailable")
+        return
+    run(
+        ["gh", "issue", "comment", str(issue_number), "--repo", repo, "--body", body],
+        check=True,
+    )
+    run(
+        ["gh", "issue", "close", str(issue_number), "--repo", repo, "--reason", "completed"],
+        check=True,
+    )
+
+
+def close_issue_as_fixed(repo: str, issue_number: int, dry_run: bool) -> None:
+    """Close the issue with a comment explaining the crash no longer reproduces."""
+    body = (
+        f"## Crash No Longer Reproduces\n\n"
+        f"This crash was retested against the latest `main` branch and "
+        f"the fuzzer completed successfully (exit code 0).\n\n"
+        f"The underlying bug appears to have been fixed. Closing this issue.\n\n"
+        f"If the crash reappears, the fuzzer will automatically open a new issue.\n\n"
+        f"---\n*{CLEANUP_MARKER}*"
+    )
+    if dry_run:
+        print(f"  [dry-run] Would close #{issue_number} as fixed")
+        return
+    run(
+        ["gh", "issue", "comment", str(issue_number), "--repo", repo, "--body", body],
+        check=True,
+    )
+    run(
+        ["gh", "issue", "close", str(issue_number), "--repo", repo, "--reason", "completed"],
+        check=True,
+    )
+
+
+def build_fuzz_target(target: str) -> bool:
+    """Build the fuzz target once. Returns True on success."""
+    print(f"\nBuilding fuzz target: {target}")
+    env = os.environ.copy()
+    env["RUSTFLAGS"] = "--cfg vortex_nightly"
+    result = run(
+        ["cargo", "+nightly", "fuzz", "build", "--dev", "--sanitizer=none", target],
+        env=env,
+    )
+    return result.returncode == 0
+
+
+def retest_crash(target: str, crash_path: str, timeout_secs: int = 120) -> str:
+    """Run the fuzz target with the crash file. Returns 'fixed', 'reproduces', or 'timeout'."""
+    env = os.environ.copy()
+    env["RUSTFLAGS"] = "--cfg vortex_nightly"
+    try:
+        result = run(
+            [
+                "cargo",
+                "+nightly",
+                "fuzz",
+                "run",
+                "--dev",
+                "--sanitizer=none",
+                target,
+                crash_path,
+                "--",
+                "-runs=1",
+                "-rss_limit_mb=0",
+            ],
+            env=env,
+            timeout=timeout_secs,
+        )
+        if result.returncode == 0:
+            return "fixed"
+        else:
+            return "reproduces"
+    except subprocess.TimeoutExpired:
+        return "timeout"
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(
+        description="Retest open fuzzer issues and close fixed ones.",
+    )
+    parser.add_argument(
+        "--target",
+        required=True,
+        help="Fuzz target to process (e.g., file_io)",
+    )
+    parser.add_argument(
+        "--repo",
+        default=os.environ.get("GITHUB_REPOSITORY", ""),
+        help="GitHub repository (owner/name). Defaults to $GITHUB_REPOSITORY.",
+    )
+    parser.add_argument(
+        "--dry-run",
+        action="store_true",
+        help="Print actions without modifying issues.",
+    )
+    args = parser.parse_args()
+
+    if not args.repo:
+        print("ERROR: --repo is required (or set GITHUB_REPOSITORY)", file=sys.stderr)
+        sys.exit(1)
+
+    print(f"Processing fuzzer issues for target={args.target} in {args.repo}")
+    if args.dry_run:
+        print("DRY RUN: no issues will be modified\n")
+
+    # 1. Fetch open fuzzer issues
+    raw_issues = fetch_open_fuzzer_issues(args.repo)
+    print(f"Found {len(raw_issues)} open fuzzer issue(s)")
+
+    # 2. Parse and filter to matching target
+    issues: list[FuzzerIssue] = []
+    for raw in raw_issues:
+        parsed = parse_issue(raw)
+        if parsed and parsed.target == args.target:
+            issues.append(parsed)
+
+    print(f"Found {len(issues)} issue(s) matching target={args.target}\n")
+    if not issues:
+        print("Nothing to do.")
+        return
+
+    # 3. Build the fuzz target once
+    if not build_fuzz_target(args.target):
+        print("ERROR: Failed to build fuzz target", file=sys.stderr)
+        sys.exit(1)
+    print()
+
+    # 4. Process each issue
+    summary: dict[str, list[int]] = {
+        "closed": [],
+        "still_reproduces": [],
+        "artifact_unavailable": [],
+        "timeout": [],
+        "error": [],
+    }
+
+    for issue in issues:
+        print(f"--- Issue #{issue.number}: {issue.title}")
+
+        # Extract run ID from artifact URL
+        if not issue.artifact_url:
+            print("  No artifact URL found in issue body")
+            if not has_cleanup_comment(args.repo, issue.number):
+                close_artifact_unavailable(args.repo, issue.number, args.dry_run)
+            else:
+                print("  Already commented about artifact unavailability, skipping")
+            summary["artifact_unavailable"].append(issue.number)
+            continue
+
+        run_id = extract_run_id(issue.artifact_url)
+        if not run_id:
+            print(f"  Could not extract run ID from: {issue.artifact_url}")
+            summary["error"].append(issue.number)
+            continue
+
+        # Download artifact into a temp directory
+        with tempfile.TemporaryDirectory() as tmpdir:
+            artifact_name = f"{args.target}-crash-artifacts"
+            dl_result = run(
+                [
+                    "gh",
+                    "run",
+                    "download",
+                    run_id,
+                    "--name",
+                    artifact_name,
+                    "--repo",
+                    args.repo,
+                    "--dir",
+                    tmpdir,
+                ],
+                capture_output=True,
+                text=True,
+            )
+
+            if dl_result.returncode != 0:
+                print(f"  Artifact download failed: {dl_result.stderr.strip()}")
+                if not has_cleanup_comment(args.repo, issue.number):
+                    close_artifact_unavailable(args.repo, issue.number, args.dry_run)
+                else:
+                    print("  Already commented about artifact unavailability, skipping")
+                summary["artifact_unavailable"].append(issue.number)
+                continue
+
+            # Locate crash file
+            crash_path = os.path.join(tmpdir, args.target, issue.crash_file)
+            if not os.path.isfile(crash_path):
+                # Try without target subdirectory (artifact structure may vary)
+                crash_path = os.path.join(tmpdir, issue.crash_file)
+                if not os.path.isfile(crash_path):
+                    print(f"  Crash file not found: {issue.crash_file}")
+                    summary["error"].append(issue.number)
+                    continue
+
+            # Retest
+            print(f"  Retesting crash file: {issue.crash_file}")
+            result = retest_crash(args.target, crash_path)
+
+            if result == "fixed":
+                print("  Crash NO LONGER reproduces — closing issue")
+                close_issue_as_fixed(args.repo, issue.number, args.dry_run)
+                summary["closed"].append(issue.number)
+            elif result == "reproduces":
+                print("  Crash STILL reproduces — leaving open")
+                summary["still_reproduces"].append(issue.number)
+            elif result == "timeout":
+                print("  Retest TIMED OUT — skipping")
+                summary["timeout"].append(issue.number)
+
+        print()
+
+    # 5. Print summary
+    print("=" * 60)
+    print("SUMMARY")
+    print("=" * 60)
+    print(f"  Closed (fixed):          {summary['closed'] or 'none'}")
+    print(f"  Still reproduces:        {summary['still_reproduces'] or 'none'}")
+    print(f"  Artifact unavailable:    {summary['artifact_unavailable'] or 'none'}")
+    print(f"  Timeout:                 {summary['timeout'] or 'none'}")
+    print(f"  Error:                   {summary['error'] or 'none'}")
+
+
+if __name__ == "__main__":
+    main()
diff --git a/.github/workflows/close-fixed-fuzzer-issues.yml b/.github/workflows/close-fixed-fuzzer-issues.yml
new file mode 100644
index 00000000000..f6dbae8445f
--- /dev/null
+++ b/.github/workflows/close-fixed-fuzzer-issues.yml
@@ -0,0 +1,59 @@
+name: Close Fixed Fuzzer Issues
+
+on:
+  schedule:
+    - cron: "0 0 * * 0"  # every Sunday at midnight UTC
+  workflow_dispatch:
+    inputs:
+      dry_run:
+        description: "Run without closing issues (retest only)"
+        type: boolean
+        default: false
+
+permissions:
+  issues: write
+  contents: read
+  actions: read
+
+jobs:
+  close-fixed:
+    name: "Retest ${{ matrix.target }}"
+    strategy:
+      fail-fast: false
+      matrix:
+        target: [file_io, array_ops, compress_roundtrip]
+    runs-on:
+      - runs-on=${{ github.run_id }}
+      - family=m8g.large
+      - image=ubuntu24-full-arm64
+      - disk=large
+      - extras=s3-cache
+      - tag=fuzzer-cleanup-${{ matrix.target }}
+    timeout-minutes: 60
+    steps:
+      - uses: runs-on/action@v2
+        with:
+          sccache: s3
+
+      - uses: actions/checkout@v6
+
+      - uses: ./.github/actions/setup-rust
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          toolchain: nightly
+
+      - name: Install llvm
+        uses: aminya/setup-cpp@v1
+        with:
+          compiler: llvm
+
+      - name: Install cargo fuzz
+        run: cargo install --locked cargo-fuzz
+
+      - name: Retest and close fixed fuzzer issues
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: >
+          python3 .github/scripts/close_fixed_fuzzer_issues.py
+          --target ${{ matrix.target }}
+          ${{ inputs.dry_run && '--dry-run' || '' }}