CVE-2026-64361 (CVSS 7.8)

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.

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CVSS v3.1 Score

7.8

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0013

Probability of exploitation

0.03%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

https://git.kernel.org/stable/c/607217f7ad419b53926f71e3f75001813bbc08ad https://git.kernel.org/stable/c/671c3fcc2ad31c1311ea6414382a2d95104ae1b9 https://git.kernel.org/stable/c/7399c3baee7bb622a92f0b895cd4d3009a693f2b https://git.kernel.org/stable/c/966cb76fb2857a4242cab6ea2ea17acf818a3da7 https://git.kernel.org/stable/c/b6a481642ea1977be2f84dc08c5affd742c177e7 https://git.kernel.org/stable/c/c25d3c931a63e762fcaa9cb125b901c53b62403f https://git.kernel.org/stable/c/c8dd112173c02adf539fe2ad34a45f5e0068780d https://git.kernel.org/stable/c/fc9d1447ca3cdc78d2e4ace1ce1f3a7c77ca08b1

Frequently Asked Questions

What is CVE-2026-64361? +

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. It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2026-64361? +

CVE-2026-64361 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0013, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-64361? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

CVE-2026-64361