CVE-2026-45541

High

Description

ESF-IDF is the Espressif Internet of Things (IOT) Development Framework. In versions 5.2.6, 5.3.5, 5.4.4, 5.5.4, and 6.0, a NULL-pointer dereference exists in the WebSocket subprotocol-negotiation path of the esp_http_server component. While parsing the client-supplied Sec-WebSocket-Protocol request header during the WebSocket handshake, the tokenisation result is dereferenced without a NULL check, so a malformed header value can crash the server before any application-level authentication runs. This issue has been patched in versions 5.2.7, 5.3.6, 5.4.5, 5.5.5, and 6.0.1.

SeverityHigh
CVSS7.5
Exploit probability—
ProductEspressif Esp-idf
PublishedJun 10, 2026
First seenJun 10, 2026

How to fix

Sources list no fixed version or patch link for this vulnerability.

Affected products

ProductAffected versionsFixed in
espressif esp-idf5.2.6, 5.3.5, 5.4.4, 5.5.4, 6.0—

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CVE-2026-45541 · Espressif Esp-idf · Dark Radar