# CVE-2026-46119: libceph: Fix slab-out-of-bounds access in auth message processing

> A slab-out-of-bounds access in the Linux kernel's Ceph client allows attackers to read memory or cause a crash via crafted auth messages.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 28 May 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-88920, BELL-CVE-2026-46119, DEBIAN-CVE-2026-46119, GHSA-7fj9-r9j7-5xwv, ROOT-OS-DEBIAN-11-CVE-2026-46119, ROOT-OS-DEBIAN-12-CVE-2026-46119, ROOT-OS-UBUNTU-2204-CVE-2026-46119, ROOT-OS-UBUNTU-2404-CVE-2026-46119, UBUNTU-CVE-2026-46119

## What is CVE-2026-46119?

CVE-2026-46119 is a critical memory corruption vulnerability in Linux kernel, published on 28 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

libceph: Fix slab-out-of-bounds access in auth message processing

If a (potentially corrupted) message of type CEPH_MSG_AUTH_REPLY
contains a positive value in its result field, it is treated as an
error code by ceph_handle_auth_reply() and returned to
handle_auth_reply(). Thereafter, an attempt is made to send the
preallocated message of type CEPH_MSG_AUTH, where the returned value is
interpreted as the size of the front segment to send. If the result
value in the message is greater than the size of the memory buffer
allocated for the front segment, an out-of-bounds access occurs, and
the content of the memory region beyond this buffer is sent out.

This patch fixes the issue by treating only negative values in the
result field as errors. Positive values are therefore treated as success
in the same way as a zero value. Additionally, a BUG_ON is added to
__send_prepared_auth_request() comparing the len parameter to
front_alloc_len to prevent sending the message if it exceeds the bounds
of the allocation and to make it easier to catch any logic flaws leading
to this.

Weakness: CWE-125 (Out-of-bounds Read), CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2026-46119?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-46119?

Apply the vendor's patch.

## Is CVE-2026-46119 being exploited?

There is no known exploitation of CVE-2026-46119 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-46119 and fix it if it is affected.

What it is: CVE-2026-46119 is a critical memory corruption vulnerability in Linux kernel, published on 28 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-46119 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2026-46119/ (Markdown: https://insights.sbomify.com/CVE-2026-46119/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-46119
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-46119
- OSV: https://osv.dev/vulnerability/CVE-2026-46119

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-46119/
Summaries are generated and may contain mistakes; the official description above is the record.