Crash via malformed L2CAP option length
Published Jul 25, 2026 · Updated Jul 25, 2026
Out-of-bounds read in the Linux Kernel L2CAP parser allows physically proximate attackers to crash the kernel via malformed options. The l2cap_get_conf_opt function reads up to four bytes from opt->val before confirming that the attacker-controlled option length fits within the remaining buffer. Reachability requires a connectable Bluetooth interface and an applicable listening service; the discarded value blocks direct disclosure in the current flow.
Summary
What happened
Out-of-bounds read in the Linux Kernel L2CAP parser allows physically proximate attackers to crash the kernel via malformed options. The l2cap_get_conf_opt function reads up to four bytes from opt->val before confirming that the attacker-controlled option length fits within the remaining buffer. Reachability requires a connectable Bluetooth interface and an applicable listening service; the discarded value blocks direct disclosure in the current flow.
The record
- CVE
- CVE-2026-64403
- Published
- Jul 25, 2026
- Updated
- Jul 25, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- T1499.004
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 25, 2026CVE publishedPublication date reported by the CVE source.
- Jul 25, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=15d6538a0d6e0f6de5116081a948cba7cc3e1d3d
- Affected versionversion=2b59d36f22622c92c0b06aee7571f0a86a217188
- Affected versionversion=3.16.66 <3.17
- Affected versionversion=3.18.138 <3.19
- Affected versionversion=4.14.110 <4.15
- Affected versionversion=4.19.33 <4.20
- Affected versionversion=4.4.178 <4.5
- Affected versionversion=4.9.167 <4.10
- Affected versionversion=5.0.6 <5.1
- Affected versionversion=5.1
- Affected versionversion=78c2887130f1a7d1883195732be1b6cdab667487
- Affected versionversion=7c9cbd0b5e38a1672fcd137894ace3b042dfbf69 <687617555cedfb74c9e3cb85d759b908dcb17856
- Affected versionversion=7c9cbd0b5e38a1672fcd137894ace3b042dfbf69 <6b47bdaacfd0045687880177e0987055d8f4765a
- Affected versionversion=7c9cbd0b5e38a1672fcd137894ace3b042dfbf69 <73abbaf91aa33da87c008fb62c148ade561bb606
- Affected versionversion=7c9cbd0b5e38a1672fcd137894ace3b042dfbf69 <7d871e969b941ce25653f7716203a0ea4d07ad4b
- Affected versionversion=7c9cbd0b5e38a1672fcd137894ace3b042dfbf69 <98d93c226bdfaa79bbdd86981921d7f106374225
- Affected versionversion=7c9cbd0b5e38a1672fcd137894ace3b042dfbf69 <996d3da39899aceb8f4910911a3f19a45a7d9d1b
- Affected versionversion=7c9cbd0b5e38a1672fcd137894ace3b042dfbf69 <cca81b4bc672604a84f6d224a55cc77ec7dee619
- Affected versionversion=7c9cbd0b5e38a1672fcd137894ace3b042dfbf69 <f70d4aa88068096f35d73e3a05eff33c0a16b9cd
- Affected versionversion=99665dcf6ff803351b5e658f3a929cb498561e36
- Affected versionversion=a556547bae00528f24b42786b41a14047db14b84
- Affected versionversion=ac7c597c465eb09391e40febbe088bdad601080b
- Affected versionversion=ade4560e4fea198866e033fe1c02f063d6d7db2e
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What is affected?
Published CVSS scores
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Attacks
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