High 7.5Published Jun 9, 2026

CVE-2026-45541ESF-IDF: Remote Null Pointer Dereference in WebSocket Server

Updated under an hour ago (Oct 27, 2026, 2:30 AM ET)

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Every CVE for espressif esp-idf

Exploited in the last 30 days

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.

CVSS: 7.5 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): CWE-476
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: Jun 10, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

espressif esp-idf espressif:esp_idf (from the name)	= 6.0; = 5.5.4; = 5.4.4; = 5.3.5; = 5.2.6	CNA record
espressif esp-idf espressif:esp-idf	5.2.6; 5.3.5; 5.4.4; 5.5.4; 6.0	NVD

References

References

https://github.com/espressif/esp-idf/security/advisories/GHSA-3j8v-xgrq-5vg8	x-refsource-confirm, mitigation, patch, vendor-advisory
https://github.com/espressif/esp-idf/commit/00a2f7fbbbd8fe6d04729022e1d5c9a49435bfe8	x-refsource-misc, patch
https://github.com/espressif/esp-idf/commit/0dc4ee7537f3b12350f5966cecacd59bba840ec6	x-refsource-misc, patch
https://github.com/espressif/esp-idf/commit/37508ab91124ef426a7396d30f79eba1162700c7	x-refsource-misc, patch
https://github.com/espressif/esp-idf/commit/9fc0ca13b3b85b98d32b98cd9dc8ff9d82642b7b	x-refsource-misc, patch
https://github.com/espressif/esp-idf/commit/dc46dc51359749e50617eb70d6f9ae298adc4fff	x-refsource-misc, patch
https://github.com/espressif/esp-idf/commit/f88a47e4f37fb11ae4b0908cd5c80059d83198c6	x-refsource-misc, patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.