CVE-2026-89726 is a vulnerability in Linux Kernel
Published on September 11, 2026
lib/ucs2_string.c: fix out-of-bounds read in ucs2_strnlen()
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.
Products Associated with CVE-2026-89726
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Affected Versions
Linux:- Version 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and below 709eb41adaf78d59d4579a13a898125919b69bcc is affected.
- Version 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and below 7d658da725ea81c91f73087547b97e7ced82d62b is affected.
- Version 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and below 1b0dc3cbb8630f0b5cb34d848628225920a904be is affected.
- Version 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and below cec0d03fe785380540dc1b4d07c80f67ae2ffc78 is affected.
- Version 2.6.12 is affected.
- Before 2.6.12 is unaffected.
- Version 6.12.109, <= 6.12.* is unaffected.
- Version 6.18.50, <= 6.18.* is unaffected.
- Version 7.2.4, <= 7.2.* is unaffected.
- Version 7.3-rc1, <= * is unaffected.