Description
Socket.IO enables bidirectional and low-latency communication for every platform. From 4.1.0 before 6.6.7, Engine.IO protocol v4 polling transport does not properly close the HTTP response for invalid binary POST requests with Content-Type: application/octet-stream, allowing an unauthenticated attacker to exhaust server-side connections and sockets. This issue is fixed in version 6.6.7.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| socketio | engine.io | >= 4.1.0, < 6.6.7 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat Hardened Images 1 | dotnet-hostfxr-8.0 +7 | 8.0.28-1.1.hum1 | RHSA-2026:37577 |
| Red Hat Hardened Images 1 | dotnet8.0 +4 | 8.0.128-1.1.hum1 | RHSA-2026:42986, RHSA-2026:37577 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | jupyter-base-notebook | 7.6.3-r2 | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| npm | engine.io | >= 4.1.0, < 6.6.7 | 6.6.7 | GHSA-r635-g3xr-vw7x |
Advisories 2
- RHSA-2026:37577 Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update Red Hat Security Advisories (RHSA) · Oct 20, 2026
- RHSA-2026:42986 Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update Red Hat Security Advisories (RHSA) · Oct 15, 2026