Cyber Resilience

CVE-2025-66409

Memory Safety in Espressif Esp-Idf ≤ 5.1.6

Memory Safety
Published
02 December 2025
Modified
13 February 2026
Patch / advisory
View advisory
CVSS Score v4 2.7
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0063 47th percentile
Risk Priority 34 floored blend · peak EPSS

Summary

CVE-2025-66409 is a low-severity Out-of-bounds Read (CWE-125) vulnerability in Espressif Esp-Idf. Its CVSS base score is 2.7 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 47th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2025-66409 is an out-of-bounds read vulnerability (CWE-125) in the Espressif IoT Development Framework (ESF-IDF), affecting versions 5.5.1, 5.4.3, 5.3.4, 5.2.6, 5.1.6, and earlier. The issue resides in the Bluetooth stack on ESP32 devices when AVRCP is enabled. It occurs when the stack processes a malformed VENDOR DEPENDENT command from a peer device, accessing memory before validating the command buffer length. This flaw carries a CVSS v3.1 base score of 9.1 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H), indicating critical severity due to high impacts on confidentiality and availability.

An attacker within Bluetooth range can exploit this vulnerability remotely without privileges or user interaction by sending a specially crafted VENDOR DEPENDENT command to a vulnerable ESP32 device with AVRCP enabled. Successful exploitation triggers an out-of-bounds read, potentially leaking sensitive memory contents or inducing unexpected behavior such as crashes or denial of service.

Mitigation requires updating to a patched version of ESF-IDF, as evidenced by fixes in the Espressif esp-idf repository. Relevant commits include 075ed218cadb8088155521cd8a795d8a626519fb, 2f788e59ee361eee230879ae2ec9cf5c893fe372, 798029129a71c802cff0e75eb59f902bca8f1946, 999710fccf95ae128fe51b5679d6b7c75c50d902, and d5db5f60fc1dcfdd8cd3ee898fdefaa272988ace, which address the buffer length validation in the Bluetooth AVRCP handling.

EU & UK References

Vulnerability Data

ESF-IDF is the Espressif Internet of Things (IOT) Development Framework. In 5.5.1, 5.4.3, 5.3.4, 5.2.6, 5.1.6, and earlier, when AVRCP is enabled on ESP32, receiving a malformed VENDOR DEPENDENT command from a peer device can cause the Bluetooth stack to…

more

access memory before validating the command buffer length. This may lead to an out-of-bounds read, potentially exposing unintended memory content or causing unexpected behavior.

CWE(s)
CWE-125

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1211 Exploitation for Stealth Stealth
Adversaries may exploit vulnerabilities to evade detection by hiding activity, suppressing logging, or operating within trusted or unmonitored components.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-25508Same product: Espressif Esp-Idf
CVE-2026-45160Same product: Espressif Esp-Idf
CVE-2026-46532Same product: Espressif Esp-Idf
CVE-2025-68474Same product: Espressif Esp-Idf
CVE-2025-68473Same product: Espressif Esp-Idf
CVE-2024-33454Same product: Espressif Esp-Idf
CVE-2026-25507Same product: Espressif Esp-Idf
CVE-2026-45542Same product: Espressif Esp-Idf
CVE-2025-55297Same product: Espressif Esp-Idf
CVE-2024-33453Same product: Espressif Esp-Idf

Affected Assets

espressif
esp-idf
≤ 5.1.6 · 5.2 — 5.2.6 · 5.3 — 5.3.4

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation directly finds out-of-bounds read flaws through static analysis, fuzzing, and dynamic bounds checks.

SA-8 Security and Privacy Engineering Principles partial match

Secure engineering principles require bounds checking and memory-safe constructs that stop out-of-bounds reads from being introduced.

SC-39 Process Isolation partial match

Process isolation confines the effects of an out-of-bounds read to the compromised process.

SI-10 Information Input Validation partial match

Input validation rejects malformed indices or lengths that would otherwise cause reads outside buffer bounds.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure-development practices such as bounds checking and memory-safe languages directly prevent out-of-bounds reads.

ID.RA-01 partial match
prevents

Vulnerability scanning and recording can discover instances of out-of-bounds reads after code is deployed.

PR.PS-02 partial match
prevents

Routine patching replaces vulnerable code containing out-of-bounds read flaws.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development and acceptance includes fuzzing and static analysis that detect out-of-bounds read defects before release.

A.8.15 Logging partial match
finds

Logging can record evidence of an out-of-bounds read but does not prevent the weakness itself.

A.8.25 Secure development life cycle partial match
prevents

Secure development life cycle mandates input validation and bounds checking that directly prevent out-of-bounds reads.

A.8.26 Application security requirements partial match
prevents

Application security requirements include explicit bounds and memory-safety specifications that mitigate buffer over-reads.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure system architecture and engineering principles require memory-safe design patterns and runtime protections against out-of-bounds access.

A.8.28 Secure coding partial match
prevents

Secure coding standards explicitly forbid unsafe pointer arithmetic and mandate bounds-checked reads, eliminating CWE-125.

References