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.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
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.
Which versions are affected by CVE-2026-46119?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-46119?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
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
Sources
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 and 3 more.