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8.1
HIGH CVSS 3.1
CVE-2025-39889
Bluetooth: l2cap: Check encryption key size on incoming connection
Overview
Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: l2cap: Check encryption key size on incoming connection This is required for passing GAP/SEC/SEM/BI-04-C PTS test case: Security Mode 4 Level 4, Responder - Invalid Encryption Key Size - 128 bit This tests the security key with size from 1 to 15 bytes while the Security Mode 4 Level 4 requests 16 bytes key size. Currently PTS fails with the following logs: - expected:Connection Response: Code: [3 (0x03)] Code Identifier: (lt)WildCard: Exists(gt) Length: [8 (0x0008)] Destination CID: (lt)WildCard: Exists(gt) Source CID: [64 (0x0040)] Result: [3 (0x0003)] Connection refused - Security block Status: (lt)WildCard: Exists(gt), but received:Connection Response: Code: [3 (0x03)] Code Identifier: [1 (0x01)] Length: [8 (0x0008)] Destination CID: [64 (0x0040)] Source CID: [64 (0x0040)] Result: [0 (0x0000)] Connection Successful Status: [0 (0x0000)] No further information available And HCI logs: < HCI Command: Read Encrypti.. (0x05|0x0008) plen 2 Handle: 14 Address: 00:1B:DC:F2:24:10 (Vencer Co., Ltd.) > HCI Event: Command Complete (0x0e) plen 7 Read Encryption Key Size (0x05|0x0008) ncmd 1 Status: Success (0x00) Handle: 14 Address: 00:1B:DC:F2:24:10 (Vencer Co., Ltd.) Key size: 7 > ACL Data RX: Handle 14 flags 0x02 dlen 12 L2CAP: Connection Request (0x02) ident 1 len 4 PSM: 4097 (0x1001) Source CID: 64 < ACL Data TX: Handle 14 flags 0x00 dlen 16 L2CAP: Connection Response (0x03) ident 1 len 8 Destination CID: 64 Source CID: 64 Result: Connection successful (0x0000) Status: No further information available (0x0000)

Details
INFO

Published Date :

Sept. 24, 2025, 11:15 a.m.

Last Modified :

Sept. 26, 2026, 12:10 a.m.

Remotely Exploit :

No

Source :

416baaa9-dc9f-4396-8d5f-8c081fb06d67
Impact
Affected Products

The following products are affected by CVE-2025-39889 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 Linux linux_kernel
: Total Affected Vendor : 1 | Products : 1
Scoring
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 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 MEDIUM [email protected]
CVSS 3.1 MEDIUM 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 HIGH 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
Apply kernel updates to enforce Bluetooth encryption key size checks.
  • Update the Linux kernel.
  • Apply security patches for Bluetooth module.
  • Reboot the system to apply changes.
  • Verify encryption key size enforcement.
References
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-2025-39889.

URL Resource
https://git.kernel.org/stable/c/24b2cdfc16e9bd6ab3d03b8e01c590755bd3141f Patch
https://git.kernel.org/stable/c/522e9ed157e3c21b4dd623c79967f72c21e45b78 Patch
https://git.kernel.org/stable/c/9e3114958d87ea88383cbbf38c89e04b8ea1bce5 Patch
https://git.kernel.org/stable/c/c6d527bbd3d3896375079f5dbc8b7f96734a3ba5 Patch
https://git.kernel.org/stable/c/d49798ecd26e0ee7995a7fc1e90ca5cd9b4402d6 Patch
https://git.kernel.org/stable/c/d4ca2fd218caafbf50e3343ba1260c6a23b5676a Patch
https://git.kernel.org/stable/c/ed503d340a501e414114ddc614a3aae4f6e9eae2
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2025-39889 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-2025-39889 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-2025-39889 vulnerability anywhere in the article.

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2025-39889 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.

  • CVE Translated by [email protected]

    Sep. 26, 2026

    Action Type Old Value New Value
    Added Translation Title: la biblioteca CGM_NIST_Loader.dll en JT2Go, Teamcenter Visualization, Description: En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta: Bluetooth: l2cap: Verificar el tamaño de la clave de cifrado en la conexión entrante Esto es necesario para aprobar el caso de prueba GAP/SEC/SEM/BI-04-C PTS: Modo de seguridad 4 Nivel 4, Respondedor - Tamaño de clave de cifrado no válido - 128 bits Esto prueba la clave de seguridad con un tamaño de 1 a 15 bytes, mientras que el Modo de seguridad 4 Nivel 4 solicita un tamaño de clave de 16 bytes. Actualmente, PTS falla con los siguientes registros: - esperado:Respuesta de conexión: Código: [3 (0x03)] Código Identificador: (lt)WildCard: Exists(gt) Longitud: [8 (0x0008)] CID de destino: (lt)WildCard: Exists(gt) CID de origen: [64 (0x0040)] Resultado: [3 (0x0003)] Conexión rechazada - Bloqueo de seguridad Estado: (lt)WildCard: Exists(gt), pero recibido:Respuesta de conexión: Código: [3 (0x03)] Código Identificador: [1 (0x01)] Longitud: [8 (0x0008)] CID de destino: [64 (0x0040)] CID de origen: [64 (0x0040)] Resultado: [0 (0x0000)] Conexión exitosa Estado: [0 (0x0000)] No hay más información disponible Y registros HCI: < Comando HCI: Leer Cifrado.. (0x05|0x0008) plen 2 Handle: 14 Dirección: 00:1B:DC:F2:24:10 (Vencer Co., Ltd.) > Evento HCI: Comando Completado (0x0e) plen 7 Leer Tamaño de Clave de Cifrado (0x05|0x0008) ncmd 1 Estado: Éxito (0x00) Handle: 14 Dirección: 00:1B:DC:F2:24:10 (Vencer Co., Ltd.) Tamaño de clave: 7 > Datos ACL RX: Handle 14 flags 0x02 dlen 12 L2CAP: Solicitud de conexión (0x02) ident 1 len 4 PSM: 4097 (0x1001) CID de origen: 64 < Datos ACL TX: Handle 14 flags 0x00 dlen 16 L2CAP: Respuesta de conexión (0x03) ident 1 len 8 CID de destino: 64 CID de origen: 64 Resultado: Conexión exitosa (0x0000) Estado: No hay más información disponible (0x0000)
  • CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Jun. 17, 2026

    Action Type Old Value New Value
    Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '4f911a538e089cce808a15dc3277250f4f8daef9', 'lessThan': 'ed503d340a501e414114ddc614a3aae4f6e9eae2', 'versionType': 'git'}, {'status': 'affected', 'version': '288c06973daae4637f25a0d1bdaf65fdbf8455f9', 'lessThan': '24b2cdfc16e9bd6ab3d03b8e01c590755bd3141f', 'versionType': 'git'}, {'status': 'affected', 'version': '288c06973daae4637f25a0d1bdaf65fdbf8455f9', 'lessThan': 'c6d527bbd3d3896375079f5dbc8b7f96734a3ba5', 'versionType': 'git'}, {'status': 'affected', 'version': '288c06973daae4637f25a0d1bdaf65fdbf8455f9', 'lessThan': '9e3114958d87ea88383cbbf38c89e04b8ea1bce5', 'versionType': 'git'}, {'status': 'affected', 'version': '288c06973daae4637f25a0d1bdaf65fdbf8455f9', 'lessThan': 'd49798ecd26e0ee7995a7fc1e90ca5cd9b4402d6', 'versionType': 'git'}, {'status': 'affected', 'version': '288c06973daae4637f25a0d1bdaf65fdbf8455f9', 'lessThan': 'd4ca2fd218caafbf50e3343ba1260c6a23b5676a', 'versionType': 'git'}, {'status': 'affected', 'version': '288c06973daae4637f25a0d1bdaf65fdbf8455f9', 'lessThan': '522e9ed157e3c21b4dd623c79967f72c21e45b78', 'versionType': 'git'}], 'programFiles': ['net/bluetooth/l2cap_core.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.11'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.11', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.15.181', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.135', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.88', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.25', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.14.4', 'versionType': 'semver', 'lessThanOrEqual': '6.14.*'}, {'status': 'unaffected', 'version': '6.15', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/bluetooth/l2cap_core.c'], 'defaultStatus': 'affected'}]
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jun. 17, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2025-39889', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-01-14T17:37:06.505788Z'}
  • CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Apr. 02, 2026

    Action Type Old Value New Value
    Added CVSS V3.1 AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
  • CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Mar. 04, 2026

    Action Type Old Value New Value
    Added Reference https://git.kernel.org/stable/c/ed503d340a501e414114ddc614a3aae4f6e9eae2
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jan. 14, 2026

    Action Type Old Value New Value
    Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
    Added CWE CWE-326
  • Initial Analysis by [email protected]

    Dec. 12, 2025

    Action Type Old Value New Value
    Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
    Added CWE CWE-326
    Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.88 *cpe:2.3:o:linux:linux_kernel:6.15:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.15:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.15.181 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.16 up to (excluding) 6.1.135 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.25 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.14.4
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/24b2cdfc16e9bd6ab3d03b8e01c590755bd3141f Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/522e9ed157e3c21b4dd623c79967f72c21e45b78 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/9e3114958d87ea88383cbbf38c89e04b8ea1bce5 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/c6d527bbd3d3896375079f5dbc8b7f96734a3ba5 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/d49798ecd26e0ee7995a7fc1e90ca5cd9b4402d6 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/d4ca2fd218caafbf50e3343ba1260c6a23b5676a Types: Patch
  • New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Sep. 24, 2025

    Action Type Old Value New Value
    Added Description In the Linux kernel, the following vulnerability has been resolved: Bluetooth: l2cap: Check encryption key size on incoming connection This is required for passing GAP/SEC/SEM/BI-04-C PTS test case: Security Mode 4 Level 4, Responder - Invalid Encryption Key Size - 128 bit This tests the security key with size from 1 to 15 bytes while the Security Mode 4 Level 4 requests 16 bytes key size. Currently PTS fails with the following logs: - expected:Connection Response: Code: [3 (0x03)] Code Identifier: (lt)WildCard: Exists(gt) Length: [8 (0x0008)] Destination CID: (lt)WildCard: Exists(gt) Source CID: [64 (0x0040)] Result: [3 (0x0003)] Connection refused - Security block Status: (lt)WildCard: Exists(gt), but received:Connection Response: Code: [3 (0x03)] Code Identifier: [1 (0x01)] Length: [8 (0x0008)] Destination CID: [64 (0x0040)] Source CID: [64 (0x0040)] Result: [0 (0x0000)] Connection Successful Status: [0 (0x0000)] No further information available And HCI logs: < HCI Command: Read Encrypti.. (0x05|0x0008) plen 2 Handle: 14 Address: 00:1B:DC:F2:24:10 (Vencer Co., Ltd.) > HCI Event: Command Complete (0x0e) plen 7 Read Encryption Key Size (0x05|0x0008) ncmd 1 Status: Success (0x00) Handle: 14 Address: 00:1B:DC:F2:24:10 (Vencer Co., Ltd.) Key size: 7 > ACL Data RX: Handle 14 flags 0x02 dlen 12 L2CAP: Connection Request (0x02) ident 1 len 4 PSM: 4097 (0x1001) Source CID: 64 < ACL Data TX: Handle 14 flags 0x00 dlen 16 L2CAP: Connection Response (0x03) ident 1 len 8 Destination CID: 64 Source CID: 64 Result: Connection successful (0x0000) Status: No further information available (0x0000)
    Added Reference https://git.kernel.org/stable/c/24b2cdfc16e9bd6ab3d03b8e01c590755bd3141f
    Added Reference https://git.kernel.org/stable/c/522e9ed157e3c21b4dd623c79967f72c21e45b78
    Added Reference https://git.kernel.org/stable/c/9e3114958d87ea88383cbbf38c89e04b8ea1bce5
    Added Reference https://git.kernel.org/stable/c/c6d527bbd3d3896375079f5dbc8b7f96734a3ba5
    Added Reference https://git.kernel.org/stable/c/d49798ecd26e0ee7995a7fc1e90ca5cd9b4402d6
    Added Reference https://git.kernel.org/stable/c/d4ca2fd218caafbf50e3343ba1260c6a23b5676a
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.
CVSS
Vulnerability Scoring Details
Base CVSS Score: 8.1
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact