Linux Kernel up to 7.2-rc5 L2CAP l2cap_le_connect_rsp use after free

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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9.5$5k-$25k0.00

Summaryinfo

A vulnerability categorized as very critical has been discovered in Linux Kernel up to 6.6.150/6.12.102/6.18.43/7.1.7/7.2-rc5. This affects the function l2cap_le_connect_rsp of the component L2CAP. Such manipulation leads to use after free. This vulnerability is referenced as CVE-2026-74540. It is possible to launch the attack remotely. No exploit is available.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.6.150/6.12.102/6.18.43/7.1.7/7.2-rc5. It has been rated as very critical. Affected by this issue is the function l2cap_le_connect_rsp of the component L2CAP. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: fix UAF in l2cap_le_connect_rsp l2cap_le_connect_rsp() obtains a channel via __l2cap_get_chan_by_ident() but neither holds a reference nor uses l2cap_chan_hold_unless_zero() before locking and operating on it. A concurrent l2cap_chan_del() triggered by a remote disconnect can free the channel between the lookup and l2cap_chan_lock(), causing a use-after-free. The BR/EDR counterpart l2cap_connect_rsp() and the sibling handler l2cap_le_command_rej() already use l2cap_chan_hold_unless_zero() to safely hold a reference, but l2cap_le_connect_rsp() was left unprotected. Fix by adding l2cap_chan_hold_unless_zero() after the ident lookup and l2cap_chan_put() on the exit path, consistent with other L2CAP response handlers.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2026-74540 since 08/15/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 08/15/2026).

Upgrading to version 6.6.151, 6.12.103, 6.18.44, 7.1.8 or 7.2-rc6 eliminates this vulnerability. Applying the patch fd4c1e301bdec60a40728ea37de531cbccda501a/522b730c62c53a1981604fd73524697fd347830d/58e3c5289ad230a7e24ae4b0c7b43f5ee6e32136/09f447accc2570751e7d17f0dc0788b40d3edade/c4740e7f23ff9a8210198d8b4703259e21b9f69d is able to eliminate this problem.

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Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 10.0
VulDB Meta Temp Score: 9.5

VulDB Base Score: 10.0
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.6.151/6.12.103/6.18.44/7.1.8/7.2-rc6
Patch: fd4c1e301bdec60a40728ea37de531cbccda501a/522b730c62c53a1981604fd73524697fd347830d/58e3c5289ad230a7e24ae4b0c7b43f5ee6e32136/09f447accc2570751e7d17f0dc0788b40d3edade/c4740e7f23ff9a8210198d8b4703259e21b9f69d

Timelineinfo

08/15/2026 Advisory disclosed
08/15/2026 +0 days CVE reserved
08/15/2026 +0 days VulDB entry created
08/15/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-74540 (🔒)
GCVE (CVE): GCVE-0-2026-74540
GCVE (VulDB): GCVE-100-390860

Entryinfo

Created: 08/15/2026 15:45
Changes: 08/15/2026 15:45 (59)
Complete: 🔍
Cache ID: 216::103

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