CVE-2026-64126: In the Linux kernel, the following vulnerability has been resolved: Bluetooth: MGMT: validate Add Extended Advertising Data length MGMT_OP_ADD_EXT_A...

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: MGMT: validate Add Extended Advertising Data length MGMT_OP_ADD_EXT_ADV_DATA is registered as a variable-length command, with MGMT_ADD_EXT_ADV_DATA_SIZE as the fixed header size. The handler then uses cp->adv_data_len and cp->scan_rsp_len to validate and copy cp->data, but it never checks that those bytes are part of the mgmt command payload. A short command can therefore make add_ext_adv_data() pass an out-of-bounds pointer into tlv_data_is_valid(). If the bytes beyond the command buffer are addressable, they can also be copied into the advertising instance as scan response data, where the caller can read them back via MGMT_OP_GET_ADV_INSTANCE. The trigger requires CAP_NET_ADMIN in the initial user namespace; KASAN reports an 8-byte slab-out-of-bounds read. Reject commands whose length does not match the fixed header plus both advertising data lengths before parsing cp->data.

Metrics

CVSS 3.1

7.3/10

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

EPSS Probability

0.14%

3.4th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

Vendor	Product	Versions
Linux	Linux	>= 12410572833a283ce92fcf9679ca8a2f372097ee, < 0d5104390b445e7bd664ad583837e4c04d892c9d; >= 12410572833a283ce92fcf9679ca8a2f372097ee, < 14b01b9cba04e6ce82825f68fc4c4322fa4ffa43; >= 12410572833a283ce92fcf9679ca8a2f372097ee, < a143ce77a5292f2c9285137433d879ce71d190a7; >= 12410572833a283ce92fcf9679ca8a2f372097ee, < a6c75a3fad226ccbd8ef9110dee87c92c299f2ab; >= 12410572833a283ce92fcf9679ca8a2f372097ee, < f1febe93ef075314615f970a87681d9ab86691d1; >= 12410572833a283ce92fcf9679ca8a2f372097ee, < 0bc1a5a69f541859293d79db72bd7854ac48df51; >= 12410572833a283ce92fcf9679ca8a2f372097ee, < d3f7d17960ed50df3a6709c5158caff989c8c905
Linux	Linux	5.11

References

Timeline

Published: Jul 19, 2026
Last Modified: Jul 30, 2026
Status: Awaiting Analysis

Frequently Asked Questions

What is CVE-2026-64126?

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: MGMT: validate Add Extended Advertising Data length MGMT_OP_ADD_EXT_ADV_DATA is registered as a variable-length command, with MGMT_ADD_EXT_ADV_DATA_SIZE as the fixed header size. The handler then uses cp->adv_data_len and cp->scan_rsp_len to validate and copy cp->data, but it never checks that those bytes are part of the mgmt command payload. A short command can therefore make add_ext_adv_data() pass an out-of-bounds pointer into tlv_data_is_valid(). If the bytes beyond the command buffer are addressable, they can also be copied into the advertising instance as scan response data, where the caller can read them back via MGMT_OP_GET_ADV_INSTANCE. The trigger requires CAP_NET_ADMIN in the initial user namespace; KASAN reports an 8-byte slab-out-of-bounds read. Reject commands whose length does not match the fixed header plus both advertising data lengths before parsing cp->data.

How severe is CVE-2026-64126?

CVE-2026-64126 has a CVSS score of 7.3/10 (HIGH severity). The EPSS model estimates a 0.14% probability of exploitation in the next 30 days.

How do I fix CVE-2026-64126?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

How Strix Helps

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