CVE-2026-45328
CRITICALESF-IDF is the Espressif Internet of Things (IOT) Development Framework. In versions 5.5.4 and 6.0, the esp_tee component exposes secure-service wrappers in esp_secure_services.c and…
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Description
ESF-IDF is the Espressif Internet of Things (IOT) Development Framework. In versions 5.5.4 and 6.0, the esp_tee component exposes secure-service wrappers in esp_secure_services.c and esp_secure_services_iram.c that bridge calls from the user application (i.e. the REE) to TEE-protected hardware peripherals (AES, SHA, ECC, HMAC, SPI, MMU, WDT) and to the security feature like attestation, OTA updates, secure storage. This issue has been patched in versions 5.5.5 and 6.0.1.
Affected Products
esp-idfespressifDetection & mitigation playbook
Vendor / applianceDetect
Inventory every espressif esp-idf deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for exploitation at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Remediation status
No patch has shipped for CVE-2026-45328 yet — track the espressif esp-idf advisory for a fixed release and apply the workarounds below in the meantime.
Mitigate without a patch
Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.
How O3 protects you
O3 detects and blocks CVE-2026-45328 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.
Tailored to CVE-2026-45328. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-45328 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2026-45328 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.