Cyber Resilience

CVE-2026-41429

Memory Safety in Espressif Arduino-Esp32 ≤ 3.3.8

Public PoCMemory Safety
Published
24 April 2026
Modified
05 May 2026
Patch / advisory
View advisory
CVSS Score v3.1 8.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0031 24th percentile
Risk Priority 63 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2026-41429 is a high-severity Stack-based Buffer Overflow (CWE-121) vulnerability in Espressif Arduino-Esp32. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 24th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — 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-2026-41429 is a remotely reachable memory corruption vulnerability, stemming from a stack-based buffer overflow (CWE-121), in the arduino-esp32 core for ESP32, ESP32-S2, ESP32-S3, ESP32-C3, ESP32-C6, and ESP32-H2 microcontrollers. The issue affects versions prior to 3.3.8 and arises in the NBNS packet handling path when NetBIOS is enabled via NBNS.begin(). In this configuration, the device listens on UDP port 137 and processes untrusted NBNS requests from the local network. The request parser trusts the attacker-controlled name_len field without bounds checking against the fixed-size destination buffers used downstream, enabling overflow.

An attacker on the adjacent network (AV:A) with no privileges (PR:N) can exploit this low-complexity (AC:L) vulnerability without user interaction (UI:N). Successful exploitation leads to high-impact confidentiality, integrity, and availability violations (C:H/I:H/A:H), with a CVSS v3.1 base score of 8.8, potentially allowing arbitrary code execution or device crashes via crafted NBNS packets.

The vulnerability is fixed in arduino-esp32 version 3.3.8, as detailed in the GitHub Security Advisory GHSA-92j9-c75g-2c5f published by Espressif. Security practitioners should update affected devices to this version and review configurations to disable NBNS if not required.

EU & UK References

Vulnerability Data

arduino-esp32 is an Arduino core for the ESP32, ESP32-S2, ESP32-S3, ESP32-C3, ESP32-C6 and ESP32-H2 microcontrollers. Prior to 3.3.8, there is a remotely reachable memory corruption issue in the NBNS packet handling path. When NetBIOS is enabled by calling NBNS.begin(...), the…

more

device listens on UDP port 137 and processes untrusted NBNS requests from the local network. The request parser trusts the attacker-controlled name_len field without enforcing a bound consistent with the fixed-size destination buffers used later in the flow. This vulnerability is fixed in 3.3.8.

CWE(s)
CWE-121

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 →
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-2026-42854Same product: Espressif Arduino-Esp32
CVE-2025-68622Same vendor: Espressif
CVE-2025-68656Same vendor: Espressif
CVE-2024-33454Same vendor: Espressif
CVE-2024-33453Same vendor: Espressif
CVE-2026-45542Same vendor: Espressif
CVE-2025-55297Same vendor: Espressif
CVE-2026-25532Same vendor: Espressif
CVE-2025-52471Same vendor: Espressif
CVE-2026-25507Same vendor: Espressif

Affected Assets

espressif
arduino-esp32
≤ 3.3.8

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 2 hardening rules · 2 OS baselines
Validate
Prove the fix (OWASP ASVS)

—

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and analysis can discover stack-buffer overflows before deployment.

SI-10 Information Input Validation good match

Input validation directly stops untrusted data from exceeding stack buffer bounds.

SI-16 Memory Protection good match

Memory-protection mechanisms limit the ability to execute injected code after a stack overflow.

SA-8 Security and Privacy Engineering Principles partial match

Secure-engineering principles include bounds-checked coding and safe buffer handling that avoid introducing the flaw.

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.

ID.RA-01 partial match
prevents

Vulnerability scanning can discover stack buffer overflows but does not prevent their introduction.

PR.PS-02 partial match
prevents

Patching eliminates known instances of the weakness after discovery.

PR.PS-06 partial match
prevents

Secure-development practices directly prevent introduction of stack buffer overflows.

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.8.25 Secure development life cycle partial match
prevents

Secure SDLC mandates buffer-safety practices that directly prevent stack overflows.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify buffer-size and input-validation rules.

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

Secure architecture principles include memory-safety and least-privilege stack usage.

A.8.28 Secure coding partial match
prevents

Secure coding standards explicitly forbid unsafe buffer handling that causes CWE-121.

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

Security testing (fuzzing, static analysis) detects stack overflows before release.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (higher-evidence rows only; rows rated `none` are excluded).

Oracle Linux 8 (1 rule)
  • V-248594 OL 8 must implement address space layout randomization (ASLR) to protect its memory from unauthorized code execution. prevents CWE-121
Oracle Linux 9 (1 rule)
  • V-271452 OL 9 must use a Linux Security Module configured to enforce limits on system services. prevents CWE-121

References