6.5
MEDIUM CVSS 3.1
CVE-2026-2411
Bluetooth GATT notify/indicate enforces the wrong attribute's permissions, bypassing encryption/authentication requirements on characteristic values
Description

Zephyr's Bluetooth host declares a GATT characteristic as two consecutive attributes: a Characteristic Declaration whose permission is hard-coded to BT_GATT_PERM_READ, and a Characteristic Value attribute that carries the application-specified security permissions (e.g. BT_GATT_PERM_READ_ENCRYPT / READ_AUTHEN / READ_LESC). The public notify and indicate APIs explicitly accept either attribute, and passing the declaration is the documented, common idiom. Before sending each notification or indication, the host re-checks link security with bt_gatt_check_perm() against params->attr in gatt_notify(), gatt_indicate(), and gatt_notify_multiple_verify_params() (subsys/bluetooth/host/gatt.c). When the application passed the Characteristic Declaration attribute, the host correctly redirected the value handle but left params->attr pointing at the declaration, so the security check evaluated the declaration's permissions (no security required) instead of the value's. As a result the encryption/authentication/LESC requirement configured on the characteristic value was skipped. The Notify-Multiple path additionally used a mask that omitted the LE Secure Connections requirement. A remote peer triggers the disclosure by connecting (optionally without pairing or encryption) and writing the Client Characteristic Configuration descriptor to enable notifications or indications, causing the server to emit the protected value over a link that has not reached the required security level. The impact is information disclosure / access-control bypass for characteristic values the application intended to expose only over a secured link; exposure depends on the application declaring encrypt/authen-required notify/indicate characteristics and on the CCC being writable at a lower security tier. There is no memory-safety or availability impact. The fix adds bt_gatt_attr_resolve_value(), which maps a declaration attribute to the following value attribute before the permission check, and switches the Notify-Multiple path to the full BT_GATT_PERM_READ_ENCRYPT_MASK so the LESC requirement is also enforced.

INFO

Published Date :

Aug. 1, 2026, 1:16 p.m.

Last Modified :

Aug. 1, 2026, 1:16 p.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2026-2411 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Zephyrproject zephyr
2 Zephyrproject zephyr
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM e2e69745-5e70-4e92-8431-deb5529a81ad
CVSS 3.1 MEDIUM [email protected]
CVSS 3.1 MEDIUM MITRE-CVE
Solution
Patch Bluetooth host to correctly check security permissions for GATT characteristic notifications and indications.
  • Apply the bt_gatt_attr_resolve_value() patch.
  • Update Notify-Multiple path for LESC enforcement.
  • Ensure GATT declaration maps to value attribute.
  • Verify security permissions on GATT characteristics.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-2411.

URL Resource
https://github.com/zephyrproject-rtos/zephyr/commit/c3386f92fe81bd10dc23e6a115e6a80a7d863546
https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-4w3r-v9q9-4462
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-2411 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-2411 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-2411 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-2411 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Aug. 01, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'zephyrproject', 'product': 'zephyr', 'versions': [{'status': 'affected', 'version': '2.6.0', 'lessThan': '4.5.0', 'versionType': 'semver'}], 'packageName': 'zephyr', 'programFiles': ['subsys/bluetooth/host/gatt.c'], 'collectionURL': 'https://github.com/zephyrproject-rtos/zephyr', 'defaultStatus': 'unaffected'}]
    Added Description Zephyr's Bluetooth host declares a GATT characteristic as two consecutive attributes: a Characteristic Declaration whose permission is hard-coded to BT_GATT_PERM_READ, and a Characteristic Value attribute that carries the application-specified security permissions (e.g. BT_GATT_PERM_READ_ENCRYPT / READ_AUTHEN / READ_LESC). The public notify and indicate APIs explicitly accept either attribute, and passing the declaration is the documented, common idiom. Before sending each notification or indication, the host re-checks link security with bt_gatt_check_perm() against params->attr in gatt_notify(), gatt_indicate(), and gatt_notify_multiple_verify_params() (subsys/bluetooth/host/gatt.c). When the application passed the Characteristic Declaration attribute, the host correctly redirected the value handle but left params->attr pointing at the declaration, so the security check evaluated the declaration's permissions (no security required) instead of the value's. As a result the encryption/authentication/LESC requirement configured on the characteristic value was skipped. The Notify-Multiple path additionally used a mask that omitted the LE Secure Connections requirement. A remote peer triggers the disclosure by connecting (optionally without pairing or encryption) and writing the Client Characteristic Configuration descriptor to enable notifications or indications, causing the server to emit the protected value over a link that has not reached the required security level. The impact is information disclosure / access-control bypass for characteristic values the application intended to expose only over a secured link; exposure depends on the application declaring encrypt/authen-required notify/indicate characteristics and on the CCC being writable at a lower security tier. There is no memory-safety or availability impact. The fix adds bt_gatt_attr_resolve_value(), which maps a declaration attribute to the following value attribute before the permission check, and switches the Notify-Multiple path to the full BT_GATT_PERM_READ_ENCRYPT_MASK so the LESC requirement is also enforced.
    Added CVSS V3.1 AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
    Added CWE CWE-863
    Added Reference https://github.com/zephyrproject-rtos/zephyr/commit/c3386f92fe81bd10dc23e6a115e6a80a7d863546
    Added Reference https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-4w3r-v9q9-4462
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.