CVE-2026-25532

Device memory corruption via WPS length underflow

Published Feb 4, 2026 · Updated Feb 4, 2026

Integer underflow in ESP-IDF 5.1.6, 5.2.6, 5.3.4, 5.4.3, and 5.5.2 allows physically proximate attackers to corrupt or reset devices. The WPS Enrollee path subtracts EAP-WSC header sizes from truncated packet lengths, then passes a negative fragment length as size_t to wpabuf_put_data(), causing an oversized heap copy; its non-fragmented path similarly requests an excessive allocation. Reachability requires the device to initiate PBC or PIN WPS pairing while a rogue access point is within Wi-Fi range, bounding impact to participating embedded devices.

CVSS severity6.3
Medium
EPSS probability0.22%
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-IDF 5.1.6, 5.2.6, 5.3.4, 5.4.3, and 5.5.2 allows physically proximate attackers to corrupt or reset devices. The WPS Enrollee path subtracts EAP-WSC header sizes from truncated packet lengths, then passes a negative fragment length as size_t to wpabuf_put_data(), causing an oversized heap copy; its non-fragmented path similarly requests an excessive allocation. Reachability requires the device to initiate PBC or PIN WPS pairing while a rogue access point is within Wi-Fi range, bounding impact to participating embedded devices.

The record

CVE
CVE-2026-25532
Published
Feb 4, 2026
Updated
Feb 4, 2026
Vendor
Espressif Systems
Product
ESP-IDF
Classifications
CWE-191, T1203
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 4, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 4, 2026Record 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== 5.2.6
  3. Affected versionversion== 5.3.4
  4. Affected versionversion== 5.4.3
  5. Affected versionversion== 5.5.2

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Espressif Systems · ESP-IDFversion== 5.1.6; version== 5.2.6; version== 5.3.4; version== 5.4.3; version== 5.5.2

Published CVSS scores

6.3GitHub, Inc.CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:N/I:L/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

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

Weakness, pattern, technique

CWE-191Integer Underflow (Wrap or Wraparound)
T1203Exploitation for Client Execution

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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