CVE-2026-102599
7.5HighPublished 13 Oct 2026 · NVD status: Awaiting Analysis
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Impact
- High impact on availability
- Weakness
- CWE-248
The AI triage for this one isn't ready yet. Check back in a few minutes; the full NVD record is below in the meantime.
CVSS v3.1 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD description
Socket.IO enables bidirectional and low-latency communication for every platform. From Engine.IO 6.6.0 until 6.6.10, a transport upgrade can independently derive an Engine.IO protocol revision from the upgrade request instead of enforcing the revision stored on the existing session. A malicious client can establish a valid session and send an upgrade request with a different or omitted EIO query parameter, attaching a transport with incompatible parser and heartbeat behavior. A crafted heartbeat packet can then trigger an uncaught exception and terminate the Node.js process, including when Engine.IO v3 compatibility is disabled because an omitted EIO value is interpreted as revision 3 on the affected path. This issue is fixed in Engine.IO 6.6.10.