CVE-2026-89726

Description

In the Linux kernel, the following vulnerability has been resolved: lib/ucs2_string.c: fix out-of-bounds read in ucs2_strnlen() Patch series "lib/ucs2_string.c: fix out-of-bounds read in ucs2_strnlen()", v2. This series fixes an off-by-one out-of-bounds read in ucs2_strnlen(). The first patch is the real fix, the second patch comes as a bonus and fixes the code indentation. This patch (of 2): ucs2_strnlen() checks the current character before checking whether the caller-provided maximum length has been reached. If the input is not NUL-terminated within that bound, the loop can read one ucs2_char_t past the limit. Test the length before dereferencing to prevent an off-by-one out-of-bounds read.

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EPSS — Exploit Prediction

0.0018

Probability of exploitation

0.07%

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/04ae68af4107600120c3c41c94268f43bc350d48 https://git.kernel.org/stable/c/1b0dc3cbb8630f0b5cb34d848628225920a904be https://git.kernel.org/stable/c/2e5a70a175f0c74e7238b013a96c4eabc3002934 https://git.kernel.org/stable/c/3ada20e110bf3245edb0a3bcddadc33d0f142f8d https://git.kernel.org/stable/c/60c74f42f5abddb85dd919b4448d5474e65dbe76 https://git.kernel.org/stable/c/709eb41adaf78d59d4579a13a898125919b69bcc https://git.kernel.org/stable/c/7d658da725ea81c91f73087547b97e7ced82d62b https://git.kernel.org/stable/c/cec0d03fe785380540dc1b4d07c80f67ae2ffc78

Frequently Asked Questions

What is CVE-2026-89726? +

In the Linux kernel, the following vulnerability has been resolved: lib/ucs2_string.c: fix out-of-bounds read in ucs2_strnlen() Patch series "lib/ucs2_string.c: fix out-of-bounds read in ucs2_strnlen()", v2. This series fixes an off-by-one out-of-bounds read in ucs2_strnlen(). The first patch is the real fix, the second patch comes as a bonus and fixes the code indentation. This patch (of 2): ucs2_strnlen() checks the current character before checking whether the caller-provided maximum length has been reached. If the input is not NUL-terminated within that bound, the loop can read one ucs2_char_t past the limit. Test the length before dereferencing to prevent an off-by-one out-of-bounds read.

How do I check if I'm vulnerable to CVE-2026-89726? +

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.