CVE-2025-39888 fuse: Block access to folio overlimit

What is CVE-2025-39888?

CVE-2025-39888 is a high-severity memory corruption vulnerability in Linux kernel, published on 23 Sep 2025. 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:

fuse: Block access to folio overlimit

syz reported a slab-out-of-bounds Write in fuse_dev_do_write.

When the number of bytes to be retrieved is truncated to the upper limit by fc->max_pages and there is an offset, the oob is triggered.

Add a loop termination condition to prevent overruns.

Weakness: CWE-787

Which versions are affected by CVE-2025-39888?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2025-39888?

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-2025-39888 being exploited?

There is no known exploitation of CVE-2025-39888 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 BELL-CVE-2025-39888, DEBIAN-CVE-2025-39888, GHSA-jgjw-jx49-6q8j, UBUNTU-CVE-2025-39888.