CVE-2026-79661: Lin-Snow ECH0

Medium severity, CVSS 6.5. EPSS: 0.4% chance of exploitation in the next 30 days.

Ech0 through 4.5.6 registers the PUT /api/echo/like/:id endpoint on the public router group without authentication or rate limiting. Unauthenticated attackers can increment the fav_count counter of any echo (including private echoes) by supplying its UUID, which can be harvested from the public GET /api/echo/page feed. Repeated requests are accepted without deduplication, each triggering a database write and a four-key cache invalidation, allowing attackers to inflate popularity metrics and amplify load on the database and cache. Fixed in 4.7.3.

Affected products

• Lin-Snow ECH0: before 4.7.3 (fixed in 4.7.3)

Published 2026-08-25. Last modified 2026-08-31.