# CVE-2026-80761: Bluetooth: ISO: zero the sockaddr before returning it in getname

> An unprivileged local attacker can leak uninitialized kernel stack memory via Bluetooth ISO socket calls, potentially exposing sensitive data.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 4 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-99594, BELL-CVE-2026-80761, DEBIAN-CVE-2026-80761, GHSA-xhh3-4cvw-88vv, UBUNTU-CVE-2026-80761

## What is CVE-2026-80761?

CVE-2026-80761 is a vulnerability in Linux, published on 4 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: ISO: zero the sockaddr before returning it in getname

iso_sock_getname() fills a struct sockaddr_iso in place and returns its
size without clearing it first, so bytes it does not write are copied to
user space from the kernel stack. The getsockname(2) and getpeername(2)
paths both run through do_getsockname(), which hands getname() an
uninitialized sockaddr_storage on the stack and copies back up to the
number of bytes getname() returns, so the driver has to initialize every
byte it accounts for.

Two ranges are left uninitialized:

  - struct sockaddr_iso is 10 bytes but only 9 are written (family,
    iso_bdaddr, iso_bdaddr_type), leaking the trailing pad byte on every
    call.

  - for a broadcast peer (BIS_LINK or PA_LINK) the returned length grows
    by sizeof(struct sockaddr_iso_bc), but only bc_sid, bc_num_bis and
    bc_bis are filled; bc_bdaddr and bc_bdaddr_type, the first 7 bytes of
    that structure, are never written.

An unprivileged process can open a BTPROTO_ISO socket and reach the pad
leak with getsockname(); the broadcast leak needs an established BIS/PA
connection. l2cap and rfcomm already memset their sockaddr in getname
for the same reason; do the same here.

## Which versions are affected by CVE-2026-80761?


## How do I fix CVE-2026-80761?

Apply the vendor's patch.

## Is CVE-2026-80761 being exploited?

There is no known exploitation of CVE-2026-80761 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80761 and fix it if it is affected.

What it is: CVE-2026-80761 is a vulnerability in Linux, published on 4 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-80761 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-80761/ (Markdown: https://insights.sbomify.com/CVE-2026-80761/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80761
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80761
- OSV: https://osv.dev/vulnerability/CVE-2026-80761

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80761/
Summaries are generated and may contain mistakes; the official description above is the record.