CVE-2026-98461: Linux kernel · Bluetooth: hci_sock: validate event length before filtering
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 4.1 Medium.
Data as of 28 Oct 2026, 01:28 UTC
CVSS:4.0/AV:P/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 18 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sock: validate event length before filtering is_filtered_packet() reads the event code from skb->data[0] without first checking that the skb is nonempty. When an opcode filter is configured, it also reads the command opcode at offsets 3 or 4 without checking that a Command Complete or Command Status event is long enough. hci_send_to_sock() invokes the filter before hci_event_packet() validates the event header. A malformed event supplied by a controller or a vhci device can therefore cause an out-of-bounds read. Keep the unmasked event code for the opcode checks. The masked value is needed for the 64-bit event bitmap, but using it to identify command events aliases event codes above 0x3f. In particular, Synchronous Train Complete (0x4f) was treated as Command Status (0x0f) even though its payload has no opcode. Reject actual command events that are too short for the field being inspected. A truncated command event cannot match a configured opcode.
References
- ubuntu.com/security/CVE-2026-98461 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-98461 (opens in a new tab)
- git.kernel.org/stable/c/1a92763c2ba721bf113cd83f913fe8c511b4a4dc (opens in a new tab)
- git.kernel.org/stable/c/ebdd49cec380731844ed9df4092a29a014623df4 (opens in a new tab)
- git.kernel.org/stable/c/2501a3b7b7144d1d11939b355a48ed01f83d0c62 (opens in a new tab)
- git.kernel.org/stable/c/dca25c204f71be0556a15177dbe037237ac43e5e (opens in a new tab)
- git.kernel.org/stable/c/39e99d85071bca0feeec3164a9437ca1bff297fc (opens in a new tab)
- git.kernel.org/stable/c/b0a6cf99afd57a39598b1beca0e86ef5004980de (opens in a new tab)
- git.kernel.org/stable/c/f894f6292d5122cd62d30600736b4a0ae79f7770 (opens in a new tab)
- git.kernel.org/stable/c/3976bbcd43b9b94c53ac9b0fd28888011588f4cc (opens in a new tab)