Is engine.io 6.6 vulnerable?

npm · 12 releases from 6.6.0 to 6.6.11 · latest engine.io is 6.6.11 · checked 1 Nov 2026

No known advisories in the last release

engine.io 6.6.11, the last 6.6 release, has no known advisories. 3 advisories affect earlier 6.6.x releases, so update to 6.6.11.

Update within 6.6:npm install engine.io@6.6.11

Is your project affected?

Private repo? Upload its lockfile instead, or connect GitHub to check every repo.

Fixed within 6.6.x, affecting earlier releases

  • HighCVE-2026-102599GHSA-2gc4-cqfq-p2gv29 Sept 2026

    Socket.IO: Engine.IO Protocol Revision Mismatch DoS

    Affected
    >=6.6.0 <6.6.10
    Fixed in
    6.6.10
  • HighCVE-2026-59724GHSA-gr94-w7qr-f4j331 Aug 2026

    Socket.IO: Engine.IO WebTransport SID DoS

    Affected
    >=6.5.0 <6.6.7
    Fixed in
    6.6.7
  • HighCVE-2026-59725GHSA-r635-g3xr-vw7x20 Jul 2026

    Socket.IO: Engine.IO Polling Transport Connection Exhaustion

    Affected
    >=4.1.0 <6.6.7
    Fixed in
    6.6.7

Which of your client projects are still on engine.io 6.6?

NPMscan reads the lockfiles in every GitHub repo you pick, finds the exact engine.io version each one installs, and checks it against these advisories. Each finding comes with the command that fixes it.

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Other engine.io versions

Advisory data from OSV.dev (opens OSV.dev in a new tab), which includes the GitHub Advisory Database. Release list from the npm registry. Refreshed daily.