patchletter vs. stack.watch

stack.watch is a free service that watches vulnerabilities for the products in your stack and sends them as an email summary — hourly to monthly, plus RSS and Slack.

patchletter takes a different angle. We follow the vendors' own release sources, pull in the demonstrably exploited flaws from CISA's KEV catalogue and record the end-of-support dates from endoflife.date. Whether you hear about it instantly, once a day or once a week is yours to set. The update radar costs nothing.

Side by side

Feature	patchletter	stack.watch
Release tracking for vendor products (Proxmox, FortiOS, Veeam …)	✓ curated vendor sources: APIs, feeds, release-notes pages	✗
Actively exploited vulnerabilities (CISA KEV)	✓ curated & low-noise — only demonstrably exploited CVEs; free to read, alert email with Pro	partly general CVE feed, no dedicated KEV curation
End-of-life / support dates	✓ endoflife.date data on every product page; warning email 90/30/7 days ahead with Pro	✗
Hardware / firmware (firewalls, NAS, switches)	✓	✗
Email instantly / daily / weekly	✓	✓
Slack / Teams / webhooks	partly Slack, Teams, webhook with Pro	partly Slack, RSS
API	✓ read-only REST API v1, free and without an account; plus an RSS feed per product	✗
Free to use	partly update emails free; security and EOL alerts with Pro	✓

When stack.watch is the better choice

Very simple to start: pick products, get a weekly CVE email — no account frills.
Covers the full CVE spectrum (NVD), not just actively exploited vulnerabilities.

Nothing wrong with running both: stack.watch for its strengths, patchletter for the vendor gear it can’t see.

Tick off what you run

Confirm your address once, and after that an email arrives as soon as one of your vendors ships a new version. That is all we need.

Browse the catalog

Facts about stack.watch verified: 2026-08. Spotted something outdated? Let us know via the legal-notice contact. All product names are trademarks of their respective owners.