CVE-2026-64361 hfs/hfsplus: fix u32 overflow in check_and_correct_requested_length
An integer overflow in the Linux kernel HFS/HFS+ filesystem allows out-of-bounds memory reads, potentially causing crashes or information disclosure.
- 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
What is CVE-2026-64361?
CVE-2026-64361 is a high-severity vulnerability in Linux kernel, published on 25 Jul 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:
hfs/hfsplus: fix u32 overflow in check_and_correct_requested_length
check_and_correct_requested_length() compares (off + len) against node_size using u32 arithmetic. When the caller passes a large len value (e.g. from an underflowed subtraction in hfs_brec_remove()), off + len can wrap past 2^32 and produce a small result, causing the bounds check to pass when it should fail.
For example, with off=14 and len=0xFFFFFFF2 (underflowed from data_off - keyoffset - size in hfs_brec_remove), off + len wraps to 6, which is less than a typical node_size of 512, so the check passes and the subsequent memmove reads ~4GB past the node buffer.
Fix this by widening the addition to u64 before comparing against node_size. This prevents the u32 wrap while keeping the logic straightforward.
Weakness: CWE-191
Which versions are affected by CVE-2026-64361?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-64361?
Apply the vendor's patch.
Is CVE-2026-64361 being exploited?
There is no known exploitation of CVE-2026-64361 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-64361, DEBIAN-CVE-2026-64361, GHSA-qpqg-q3fj-94c5, ROOT-OS-DEBIAN-12-CVE-2026-64361, ROOT-OS-DEBIAN-13-CVE-2026-64361, ROOT-OS-UBUNTU-2204-CVE-2026-64361 and 1 more.