CVE-2026-33151

Impact

A specially crafted Socket.IO packet can make the server wait for a large number of binary attachments and buffer them, which can be exploited to make the server run out of memory.

Patches

Version range	Used by	Fixed version
>=4.0.0 <4.2.6	socket.io@4.x and socket.io-client@4.x	4.2.6
>=3.4.0 <3.4.4	socket.io@2.x	3.4.4
<3.3.5	socket.io-client@2.x	3.3.5

Workarounds

There is no known workaround except upgrading to a safe version.

For more information

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