CVE-2025-21748 ksmbd: fix integer overflows on 32 bit systems

What is CVE-2025-21748?

CVE-2025-21748 is a critical vulnerability in Linux kernel, published on 27 Feb 2025. 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:

ksmbd: fix integer overflows on 32 bit systems

On 32bit systems the addition operations in ipc_msg_alloc() can potentially overflow leading to memory corruption. Add bounds checking using KSMBD_IPC_MAX_PAYLOAD to avoid overflow.

Weakness: CWE-190

Which versions are affected by CVE-2025-21748?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2025-21748?

Apply the vendor's patch.

Is CVE-2025-21748 being exploited?

There is no known exploitation of CVE-2025-21748 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-57795, BELL-CVE-2025-21748, DEBIAN-CVE-2025-21748, GHSA-6hjx-r579-83fp, ROOT-OS-UBUNTU-2404-CVE-2025-21748, UBUNTU-CVE-2025-21748.