CVE-2026-89583 Bluetooth: eir: Fix OOB read in eir_get_service_data()
A remote attacker can trigger an out-of-bounds read in the Linux kernel Bluetooth stack to disclose sensitive memory contents via crafted advertising data.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-89583?
CVE-2026-89583 is a high-severity vulnerability in Linux, published on 11 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-89583?
How do I fix CVE-2026-89583?
Apply the vendor's patch.
Is CVE-2026-89583 being exploited?
There is no known exploitation of CVE-2026-89583 in the wild and no public exploit code.
Sources
Also known as AZL-100524, BELL-CVE-2026-89583, DEBIAN-CVE-2026-89583, GHSA-q3pj-rcr4-5rqx, UBUNTU-CVE-2026-89583.