CVE-2026-64403Bluetooth: L2CAP: validate option length before reading conf opt value
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 7.1 HIGH (v3.1, CNA)CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Analyzed
- Record last updated
- Oct 16, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from 7c9cbd0b5e38a1672fcd137894ace3b042dfbf69 before cca81b4bc672604a84f6d224a55cc77ec7dee619; from 7c9cbd0b5e38a1672fcd137894ace3b042dfbf69 before f70d4aa88068096f35d73e3a05eff33c0a16b9cd; from 7c9cbd0b5e38a1672fcd137894ace3b042dfbf69 before 7d871e969b941ce25653f7716203a0ea4d07ad4b; from 7c9cbd0b5e38a1672fcd137894ace3b042dfbf69 before 98d93c226bdfaa79bbdd86981921d7f106374225; from 7c9cbd0b5e38a1672fcd137894ace3b042dfbf69 before 996d3da39899aceb8f4910911a3f19a45a7d9d1b; from 7c9cbd0b5e38a1672fcd137894ace3b042dfbf69 before 73abbaf91aa33da87c008fb62c148ade561bb606; 7c9cbd0b5e38a1672fcd137894ace3b042dfbf69 builds before 6b47bdaacfd0045687880177e0987055d8f4765a; from 7c9cbd0b5e38a1672fcd137894ace3b042dfbf69 before 687617555cedfb74c9e3cb85d759b908dcb17856; and 14 more ranges | CNA record |
linux linux_kernel linux:linux_kernel | from 3.16.66 before 3.17; from 3.18.138 before 3.19; from 4.4.178 before 4.5; from 4.9.167 before 4.10; from 4.14.110 before 4.15; from 4.19.33 before 4.20; from 5.0.6 before 5.10.261; from 5.11 before 5.15.212; and 7 more ranges | NVD |
References
- https://git.kernel.org/stable/c/cca81b4bc672604a84f6d224a55cc77ec7dee619patch
- https://git.kernel.org/stable/c/f70d4aa88068096f35d73e3a05eff33c0a16b9cdpatch
- https://git.kernel.org/stable/c/7d871e969b941ce25653f7716203a0ea4d07ad4bpatch
- https://git.kernel.org/stable/c/98d93c226bdfaa79bbdd86981921d7f106374225patch
- https://git.kernel.org/stable/c/996d3da39899aceb8f4910911a3f19a45a7d9d1bpatch
- https://git.kernel.org/stable/c/73abbaf91aa33da87c008fb62c148ade561bb606patch
- https://git.kernel.org/stable/c/6b47bdaacfd0045687880177e0987055d8f4765apatch
- https://git.kernel.org/stable/c/687617555cedfb74c9e3cb85d759b908dcb17856patch
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.