CVE-2026-45541
ESF-IDF: Remote Null Pointer Dereference in WebSocket Server
CVSS Score
7.5
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-476 |
| Vendor | espressif |
| Product | esp-idf |
| Published | Jun 10, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Affected Versions
espressif / esp-idf
= 6.0 = 5.5.4 = 5.4.4 = 5.3.5 = 5.2.6
References
github.com: https://github.com/espressif/esp-idf/security/advisories/GHSA-3j8v-xgrq-5vg8 github.com: https://github.com/espressif/esp-idf/commit/00a2f7fbbbd8fe6d04729022e1d5c9a49435bfe8 github.com: https://github.com/espressif/esp-idf/commit/0dc4ee7537f3b12350f5966cecacd59bba840ec6 github.com: https://github.com/espressif/esp-idf/commit/37508ab91124ef426a7396d30f79eba1162700c7 github.com: https://github.com/espressif/esp-idf/commit/9fc0ca13b3b85b98d32b98cd9dc8ff9d82642b7b github.com: https://github.com/espressif/esp-idf/commit/dc46dc51359749e50617eb70d6f9ae298adc4fff github.com: https://github.com/espressif/esp-idf/commit/f88a47e4f37fb11ae4b0908cd5c80059d83198c6