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Fencer Intel
medium 6.5

CVE-2026-81507 json

ESF-IDF: Bluetooth Classic L2CAP Heap Memory Disclosure Allowing Unauthorized Access to Sensitive Data

published 2mo ago modified 26d ago also EUVD-2026-98738 , GHSA-v335-fxwc-rc44

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository espressif/esp-idf. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 18%
public exploits
0
none known

Summary

ESF-IDF is the Espressif Internet of Things (IOT) Development Framework. Prior to 5.2.8, 5.3.6, 5.5.5, 6.0.3, and 6.1-rc1, ESP-IDF BlueDroid L2CAP configuration-option processing in l2c_main.c and l2c_utils.c does not consistently validate option lengths against the remaining received packet bytes. A remote unauthenticated BR/EDR peer within radio range can send a malformed L2CAP configuration request that causes an out-of-bounds read, and under some runtime conditions limited adjacent Bluetooth stack memory can be included in an outbound L2CAP Configuration Response. The issue affects ESP32-class products using the BlueDroid host stack with Classic Bluetooth enabled. This issue is fixed in 5.2.8, 5.3.6, 5.5.5, 6.0.3, and 6.1-rc1.

Patch / fix

  • espressif esp-idf 5.2.8, 5.3.6, 5.5.5, 6.0.3, 6.1-rc1

Is CVE-2026-81507 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
28d ago

Exploit prediction

0.26% chance of exploitation in the next 30 days, higher than 18% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected products

  • espressif esp-idf

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of espressif/esp-idf published their own advisory on GitHub. Reviewed sources take precedence over it.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.