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.
CVE-2026-45541
HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence
This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 65% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: epss, secondary
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.5Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 7.5
- EG Score
- 7.5(medium)
- EPSS
- 35.5%
- KEV
- Not listed
Published
June 10, 2026
Last Modified
June 11, 2026
Advisory Details (7)
Auto-updated Jun 10, 2026Patch available. Sources: github_commit, github.
github Patch Available
Remote Null Pointer Dereference in WebSocket Server · Advisory · espressif/esp-idf · GitHub
https://github.com/espressif/esp-idf/security/advisories/GHSA-3j8v-xgrq-5vg8github_commit
commit f88a47e4f37f (espressif/esp-idf)
Fix landed in espressif/esp-idf commit f88a47e4f37f — awaiting tagged release
https://github.com/espressif/esp-idf/commit/f88a47e4f37fb11ae4b0908cd5c80059d83198c6github_commit
commit dc46dc513597 (espressif/esp-idf)
Fix landed in espressif/esp-idf commit dc46dc513597 — awaiting tagged release
https://github.com/espressif/esp-idf/commit/dc46dc51359749e50617eb70d6f9ae298adc4fffgithub_commit
commit 9fc0ca13b3b8 (espressif/esp-idf)
Fix landed in espressif/esp-idf commit 9fc0ca13b3b8 — awaiting tagged release
https://github.com/espressif/esp-idf/commit/9fc0ca13b3b85b98d32b98cd9dc8ff9d82642b7bgithub_commit
commit 37508ab91124 (espressif/esp-idf)
Fix landed in espressif/esp-idf commit 37508ab91124 — awaiting tagged release
https://github.com/espressif/esp-idf/commit/37508ab91124ef426a7396d30f79eba1162700c7github_commit
commit 0dc4ee7537f3 (espressif/esp-idf)
Fix landed in espressif/esp-idf commit 0dc4ee7537f3 — awaiting tagged release
https://github.com/espressif/esp-idf/commit/0dc4ee7537f3b12350f5966cecacd59bba840ec6github_commit
commit 00a2f7fbbbd8 (espressif/esp-idf)
Fix landed in espressif/esp-idf commit 00a2f7fbbbd8 — awaiting tagged release
https://github.com/espressif/esp-idf/commit/00a2f7fbbbd8fe6d04729022e1d5c9a49435bfe8Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-45541?
CVE-2026-45541 is a high vulnerability published on June 10, 2026. 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 esphttpserver component. While parsing the client-supplied Sec-WebSocket-Protocol request…
When was CVE-2026-45541 disclosed?
CVE-2026-45541 was first published in the National Vulnerability Database on June 10, 2026, with the most recent update on June 11, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-45541 actively exploited?
CVE-2026-45541 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 35.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-45541?
CVE-2026-45541 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-45541?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-45541, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-45541
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