CVE-2025-52471Network attack vector

Remote code execution via ESP-NOW length underflow

Published Jun 24, 2025 · Updated Jun 24, 2025

Integer underflow in ESP-NOW reception in Espressif Systems ESP-IDF 5.1.6, 5.2.5, 5.3.3, and 5.4.1 allows remote attackers to write memory. The packet receive function fails to validate a supplied data length before a subtraction, allowing a negative calculation to produce out-of-bounds access and an arbitrary memory write. Exploitation requires a crafted ESP-NOW packet; code execution is limited to targets without memory protection.

CVSS severity9.8
Critical
EPSS probability0.85%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer underflow in ESP-NOW reception in Espressif Systems ESP-IDF 5.1.6, 5.2.5, 5.3.3, and 5.4.1 allows remote attackers to write memory. The packet receive function fails to validate a supplied data length before a subtraction, allowing a negative calculation to produce out-of-bounds access and an arbitrary memory write. Exploitation requires a crafted ESP-NOW packet; code execution is limited to targets without memory protection.

The record

CVE
CVE-2025-52471
Published
Jun 24, 2025
Updated
Jun 24, 2025
Vendor
Espressif Systems
Product
ESP-IDF
Classifications
CWE-191, T1210
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 24, 2025CVE publishedPublication date reported by the CVE source.
  2. Jun 24, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion== 5.1.6
  2. Affected versionversion== 5.2.5
  3. Affected versionversion== 5.3.3
  4. Affected versionversion== 5.4.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Espressif Systems · ESP-IDFversion== 5.1.6; version== 5.2.5; version== 5.3.3; version== 5.4.1

Published CVSS scores

7.2GitHubCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U
9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-191Integer Underflow (Wrap or Wraparound)
T1210Exploitation of Remote Services

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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