CVE-2026-55537

### Summary `praisonai/jobs/models.py::JobSubmitRequest.validate_webhook_url()` validates webhook URLs by resolving the hostname and checking whether the IP is private. When DNS resolution fails (`socket.gaierror`), the validator **silently passes** the URL via `except socket.gaierror: pass`. Additionally, even when DNS succeeds at validation time, the webhook is fired much later by `JobExecutor._send_webhook()`, which calls `httpx.AsyncClient().post(job.webhook_url)` — performing a **fresh, independent DNS lookup** at execution time. Together, these flaws create a TOCTOU SSRF window. An attacker can: 1. Submit a job with `webhook_url` pointing to a hostname that currently does not resolve (NXDOMAIN) → validation passes (`gaierror` → `pass`) 2. Update DNS to point that hostname to `127.0.0.1` or another private IP 3. When the job completes, `_send_webhook()` resolves the hostname fresh → POST sent to the internal IP ### Details **Flaw 1 — Fail-open on DNS error (`jobs/models.py` lines 58-66):** ```python @field_validator("webhook_url") @classmethod def validate_webhook_url(cls, v): ... try: ip = socket.gethostbyname(hostname) ip_obj = ipaddress.ip_address(ip) if ip_obj.is_private or ip_obj.is_loopback or ip_obj.is_link_local: raise ValueError("Webhook URL resolves to private network address") except socket.gaierror: pass # <-- FAIL-OPEN: DNS failure allows the URL without restriction return v ``` When `socket.gethostbyname(hostname)` raises `socket.gaierror` (NXDOMAIN, timeout, network error during validation), execution flows to `pass` and the URL is accepted. **Flaw 2 — Fresh DNS at execution time (`jobs/executor.py` lines 376-406):** ```python async def _send_webhook(self, job: Job): async with httpx.AsyncClient(timeout=30.0) as client: response = await client.post( job.webhook_url, # <-- fresh DNS resolution here, not cached from validation json=