NULL pointer dereference in Espressif Esp-Idf

CVE-2026-45541

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.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.008 (55.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 56th percentile — 55.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-45541: held from 0.004 to 0.008.

EPSS over last 30 days · oldest: 0.004 · newest: 0.008 · change: +0.004

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-45541?
CVE-2026-45541 is a high-severity vulnerability in Espressif Esp-Idf, classified under NULL Pointer Dereference. CVSS score: 7.5/10. Published 2026-06-10.
How severe is CVE-2026-45541?
High severity. CVSS v3 base score is 7.5 out of 10.