SECUFOCUSNOW
Home›CVE index›CVE-2026-64539
Review reviewHigh

CVE-2026-64539

Linux

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: eir: Fix stack OOB write when prepending the Flags AD eir_create_adv_data() builds the advertising data into a fixed-size buffer ("size", 31 for the legacy path). It may prepend a 3-byte "Flags" AD structure (LE_AD_NO_BREDR on an LE-only controller) and then copies the per-instance data without checking that it still fits: memcpy(ptr, adv->adv_data, adv->adv_data_len); tlv_data_max_len() only reserves those 3 bytes when the user-supplied flags carry a managed-flags bit, so an instance added with flags == 0 is acc...

CVSS
7.8
EPSS
-
- percentile
CISA KEV
Not listed
Published
2026.07.28
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability-
Technical severityCVSS 7.8

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: eir: Fix stack OOB write when prepending the Flags AD eir_create_adv_data() builds the advertising data into a fixed-size buffer ("size", 31 for the legacy path). It may prepend a 3-byte "Flags" AD structure (LE_AD_NO_BREDR on an LE-only controller) and then copies the per-instance data without checking that it still fits: memcpy(ptr, adv->adv_data, adv->adv_data_len); tlv_data_max_len() only reserves those 3 bytes when the user-supplied flags carry a managed-flags bit, so an instance added with flags == 0 is acc...

Affected product and versions

Product
Linux
Affected versions
>= b44133ff03be30b55f23036e62f403a3f7784fce < 0f0b6232af56441d0a2dcb173cc4f8d8aab39014, >= b44133ff03be30b55f23036e62f403a3f7784fce < 09301f1fdf2aef8cce34d0c4650c30e7edb1ced9, >= b44133ff03be30b55f23036e62f403a3f7784fce < f1b4df9c260c51726da2e86e19322825fddeefd0, >= b44133ff03be30b55f23036e62f403a3f7784fce < 57077eeb586c42f124bc09e018449362223067b3, >= b44133ff03be30b55f23036e62f403a3f7784fce < 6f5fb689fdf80bdd143f22a502f9eb1f3c85e286, >= 4.1
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
Not available