# CVE-2026-45541: Espressif ESP-IDF NULL pointer dereference in esp_http_server

Source: https://junglewise.ai/threats/cve-2026-45541-espressif-esp-idf-null-pointer-dereference-in-esp-http-server  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-10. Updated: 2026-06-10  
License: CC BY 4.0 with a link back

CVE-2026-45541 · Severity: high · CVSS 7.5 · Published 2026-06-10

Espressif ESP-IDF is a development framework used to build software for Internet of Things (IoT) devices. A flaw in its built-in web server component allows an attacker to crash the device remotely by sending a specially crafted network request. This can lead to a complete service outage for the affected IoT device before any security login or authentication occurs.

Technologies: [Espressif Systems ESP-IDF](https://junglewise.ai/threats/technologies/esp-idf). Vendors: [Espressif Systems](https://junglewise.ai/threats/vendors/espressif-systems).

## Quick answers

**Is CVE-2026-45541 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-45541 being exploited in the wild.

**How severe is CVE-2026-45541?** High severity, with a CVSS score of 7.5, published 10 June 2026.

**Which products and versions are affected?** Espressif Systems ESP-IDF 5.2.6, 5.3.5, 5.4.4, 5.5.4, 6.0.

**Is there a fix for CVE-2026-45541?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-45541 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-45541?** Check whether you run Espressif Systems ESP-IDF at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A NULL-pointer dereference (CWE-476) exists in the 'esp_http_server' component of the ESP-IDF framework. The vulnerability is located within the 'httpd_ws_get_response_subprotocol' function in 'httpd_ws.c', where the result of a 'strtok_r' operation on the 'Sec-WebSocket-Protocol' request header is dereferenced without a prior NULL check. An unauthenticated remote attacker can exploit this by sending a malformed WebSocket handshake request, causing the server to crash (Denial of Service). The issue is patched in versions 5.2.7, 5.3.6, 5.4.5, 5.5.5, and 6.0.1.

## Affected products

- Espressif Systems ESP-IDF 5.2.6, 5.3.5, 5.4.4, 5.5.4, 6.0

## Timeline

- 2026-05-15: advisory: GitHub Security Advisory GHSA-3j8v-xgrq-5vg8 published
- 2026-06-10: disclosed: CVE-2026-45541 published to NVD

## References

- [https://github.com/espressif/esp-idf/commit/00a2f7fbbbd8fe6d04729022e1d5c9a49435bfe8](https://github.com/espressif/esp-idf/commit/00a2f7fbbbd8fe6d04729022e1d5c9a49435bfe8)
- [https://github.com/espressif/esp-idf/commit/0dc4ee7537f3b12350f5966cecacd59bba840ec6](https://github.com/espressif/esp-idf/commit/0dc4ee7537f3b12350f5966cecacd59bba840ec6)
- [https://github.com/espressif/esp-idf/commit/37508ab91124ef426a7396d30f79eba1162700c7](https://github.com/espressif/esp-idf/commit/37508ab91124ef426a7396d30f79eba1162700c7)
- [https://github.com/espressif/esp-idf/commit/9fc0ca13b3b85b98d32b98cd9dc8ff9d82642b7b](https://github.com/espressif/esp-idf/commit/9fc0ca13b3b85b98d32b98cd9dc8ff9d82642b7b)
- [https://github.com/espressif/esp-idf/commit/dc46dc51359749e50617eb70d6f9ae298adc4fff](https://github.com/espressif/esp-idf/commit/dc46dc51359749e50617eb70d6f9ae298adc4fff)
- [https://github.com/espressif/esp-idf/commit/f88a47e4f37fb11ae4b0908cd5c80059d83198c6](https://github.com/espressif/esp-idf/commit/f88a47e4f37fb11ae4b0908cd5c80059d83198c6)
- [https://github.com/espressif/esp-idf/security/advisories/GHSA-3j8v-xgrq-5vg8](https://github.com/espressif/esp-idf/security/advisories/GHSA-3j8v-xgrq-5vg8)

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- [Espressif ESP-IDF Out-of-Bounds Read in ESP-TEE Secure Service Wrappers](https://junglewise.ai/threats/cve-2026-45329-espressif-esp-idf-out-of-bounds-read-in-esp-tee-secure-service)
- [Espressif ESP-IDF out-of-bounds write in esp_tee component](https://junglewise.ai/threats/cve-2026-45328-espressif-esp-idf-out-of-bounds-write-in-esp-tee-component)