Linux Kernel up to 7.2-rc2 Bluetooth L2CAP l2cap_get_conf_opt len/val out-of-bounds

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6.2	$0-$5k	2.33-

Summaryinfo

A vulnerability classified as critical has been found in Linux Kernel up to 7.2-rc2. This affects the function l2cap_get_conf_opt of the component Bluetooth L2CAP. Performing a manipulation of the argument len/val results in out-of-bounds. This vulnerability was named CVE-2026-64403. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability classified as critical has been found in Linux Kernel up to 7.2-rc2. This affects the function l2cap_get_conf_opt of the component Bluetooth L2CAP. The manipulation of the argument len/val with an unknown input leads to a out-of-bounds vulnerability. CWE is classifying the issue as CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. This is going to have an impact on integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: validate option length before reading conf opt value l2cap_get_conf_opt() derives the option length from the attacker-controlled opt->len field and immediately dereferences opt->val (as u8, get_unaligned_le16() or get_unaligned_le32(), or a raw pointer for the default case) before any caller has confirmed that opt->len bytes are present in the buffer. The callers (l2cap_parse_conf_req(), l2cap_parse_conf_rsp() and l2cap_conf_rfc_get()) only detect a malformed option afterwards, once the running length has gone negative, by which point the out-of-bounds read has already executed. An existing post-hoc length check keeps the garbage value from being consumed, so this is not a data leak in the current control flow. It is still a validate-after-use ordering bug: up to 4 bytes are read past the end of the buffer before it is known to contain them, and it is fragile to future changes in the callers. Fix it at the source. Pass the end of the buffer into l2cap_get_conf_opt() and refuse to touch opt->val unless the full option (header + value) fits. Each caller computes an end pointer once before the loop and checks the return value directly instead of inferring the error from a negative length.

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-64403 since 07/19/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 07/25/2026).

Upgrading to version 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.96, 6.18.39, 7.1.4 or 7.2-rc3 eliminates this vulnerability. Applying the patch cca81b4bc672604a84f6d224a55cc77ec7dee619/f70d4aa88068096f35d73e3a05eff33c0a16b9cd/7d871e969b941ce25653f7716203a0ea4d07ad4b/98d93c226bdfaa79bbdd86981921d7f106374225/996d3da39899aceb8f4910911a3f19a45a7d9d1b/73abbaf91aa33da87c008fb62c148ade561bb606/6b47bdaacfd0045687880177e0987055d8f4765a/687617555cedfb74c9e3cb85d759b908dcb17856 is able to eliminate this problem.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.10.260
• 5.15.211
• 6.1.177
• 6.6.144
• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
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• 6.12.88
• 6.12.89
• 6.12.90
• 6.12.91
• 6.12.92
• 6.12.93
• 6.12.94
• 6.12.95
• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
• 6.18.9
• 6.18.10
• 6.18.11
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• 6.18.31
• 6.18.32
• 6.18.33
• 6.18.34
• 6.18.35
• 6.18.36
• 6.18.37
• 6.18.38
• 7.1.0
• 7.1.1
• 7.1.2
• 7.1.3
• 7.2-rc1
• 7.2-rc2

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.5
VulDB Meta Temp Score: 6.2

VulDB Base Score: 6.5
VulDB Temp Score: 6.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds
CWE: CWE-125 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.10.261/5.15.212/6.1.178/6.6.145/6.12.96/6.18.39/7.1.4/7.2-rc3
Patch: cca81b4bc672604a84f6d224a55cc77ec7dee619/f70d4aa88068096f35d73e3a05eff33c0a16b9cd/7d871e969b941ce25653f7716203a0ea4d07ad4b/98d93c226bdfaa79bbdd86981921d7f106374225/996d3da39899aceb8f4910911a3f19a45a7d9d1b/73abbaf91aa33da87c008fb62c148ade561bb606/6b47bdaacfd0045687880177e0987055d8f4765a/687617555cedfb74c9e3cb85d759b908dcb17856

Timelineinfo

07/19/2026 CVE reserved
07/25/2026 +6 days Advisory disclosed
07/25/2026 +0 days VulDB entry created
07/25/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-64403 (🔒)
GCVE (CVE): GCVE-0-2026-64403
GCVE (VulDB): GCVE-100-383193

Entryinfo

Created: 07/25/2026 18:22
Changes: 07/25/2026 18:22 (60)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion

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