CVE-2026-81507

Memory disclosure via unchecked L2CAP option lengths

Published Oct 13, 2026 · Updated Oct 13, 2026

Out-of-bounds reads in Espressif Systems ESP-IDF BlueDroid L2CAP allow remote attackers to read stack memory via crafted Bluetooth requests. Configuration-option processing in l2c_main.c and l2c_utils.c reads option data without consistently checking its length against the remaining packet bytes. Exposure requires Classic Bluetooth enabled on an ESP32-class device and an unauthenticated peer within radio range; under some runtime conditions, Configuration Responses disclose limited adjacent Bluetooth stack memory.

CVSS severity6.5
Medium
EPSS probability0.26%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds reads in Espressif Systems ESP-IDF BlueDroid L2CAP allow remote attackers to read stack memory via crafted Bluetooth requests. Configuration-option processing in l2c_main.c and l2c_utils.c reads option data without consistently checking its length against the remaining packet bytes. Exposure requires Classic Bluetooth enabled on an ESP32-class device and an unauthenticated peer within radio range; under some runtime conditions, Configuration Responses disclose limited adjacent Bluetooth stack memory.

The record

CVE
CVE-2026-81507
Published
Oct 13, 2026
Updated
Oct 13, 2026
Vendor
Espressif Systems
Product
ESP-IDF
Classifications
CWE-125
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 13, 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=< 5.2.8
  2. Affected versionversion=>= 5.3-beta1, < 5.3.6
  3. Affected versionversion=>= 5.4-beta1, < 5.5.5
  4. Affected versionversion=>= 6.0-beta1, < 6.0.3
  5. Affected versionversion=>= 6.1-beta1, < 6.1-rc1

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Espressif Systems · ESP-IDFversion=< 5.2.8; version=>= 5.3-beta1, < 5.3.6; version=>= 5.4-beta1, < 5.5.5; version=>= 6.0-beta1, < 6.0.3; version=>= 6.1-beta1, < 6.1-rc1

Published CVSS scores

6.5GitHub_MCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

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.

Activity data is delayed. The latest report is Sep 28, 2026.

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

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read

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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