ruvnet/ruflo · error · Error

Header JSON exceeds maximum size (${headerLen} > ${MAX_HEADE

Error message

Header JSON exceeds maximum size (${headerLen} > ${MAX_HEADER_JSON_SIZE})

What it means

Thrown by RvfaReader.fromBuffer() when the declared header JSON length (u32LE at offset 8) exceeds MAX_HEADER_JSON_SIZE (1 MiB). This is a sanity cap that rejects absurd or hostile header-length fields before attempting a multi-megabyte allocation and JSON.parse. The magic and version checks already passed.

Source

Thrown at v3/@claude-flow/cli/src/appliance/rvfa-format.ts:332

    // Magic
    const magic = buf.subarray(0, MAGIC_SIZE).toString('ascii');
    if (magic !== 'RVFA') {
      throw new Error(`Invalid RVFA magic: expected "RVFA", got "${magic}"`);
    }

    // Version
    const version = buf.readUInt32LE(MAGIC_SIZE);
    if (version !== RVFA_VERSION) {
      throw new Error(
        `Unsupported RVFA version: ${version} (expected ${RVFA_VERSION})`,
      );
    }

    // Header length
    const headerLen = buf.readUInt32LE(MAGIC_SIZE + VERSION_SIZE);
    if (headerLen > MAX_HEADER_JSON_SIZE) {
      throw new Error(
        `Header JSON exceeds maximum size (${headerLen} > ${MAX_HEADER_JSON_SIZE})`,
      );
    }
    if (PREAMBLE_SIZE + headerLen > buf.length) {
      throw new Error('Buffer too small to contain declared header');
    }

    // Parse header JSON
    const headerSlice = buf.subarray(PREAMBLE_SIZE, PREAMBLE_SIZE + headerLen);
    let parsed: unknown;
    try {
      parsed = JSON.parse(headerSlice.toString('utf-8'));
    } catch {
      throw new Error('Failed to parse RVFA header JSON');
    }

    if (!validateHeader(parsed)) {
      throw new Error('RVFA header failed validation');

View on GitHub (pinned to 6b01dc5a68)

Solutions

1. Discard the appliance file — a header length above 1 MiB is never legitimate for the current format.
2. Regenerate the appliance from source via RvfaBuilder.build().
3. If accepting untrusted appliances, keep this check as a resource-exhaustion guard.
4. Verify the file was not truncated or concatenated with another binary.

const MAX_HEADER = 1024 * 1024;
function headerLenWithinMax(buf: Buffer): boolean {
  if (buf.length < 12) return false;
  const hLen = buf.readUInt32LE(8);
  return hLen <= MAX_HEADER;
}

try {
  const reader = RvfaReader.fromBuffer(buf);
} catch (e) {
  if (/Header JSON exceeds maximum size/.test((e as Error).message)) {
    throw new Error('Header length field is implausibly large; the appliance is corrupt or hostile');
  }
  throw e;
}

When it happens

Trigger: A corrupted 4-byte header-length field that decodes to a huge value (e.g. due to byte rotation), or a deliberately crafted malicious appliance designed to cause memory exhaustion. Random corruption of the length field commonly produces values far above 1 MiB.

Common situations: Bit-rot or partial overwrite of the header-length bytes; a fuzzer or adversarial input; a file produced by a buggy writer that mis-encoded the length.

Related errors

• RVFA header failed validation
• Validation failed: ${result.error}
• Buffer too small to contain RVFA preamble
• Invalid RVFA magic: expected "RVFA", got "${magic}"
• Failed to parse RVFA header JSON

AI-assisted analysis of ruvnet/ruflo@6b01dc5a68 (2026-08-12). Data as JSON: /api/errors/8dd85ebb5e942853. Report an issue: GitHub.