{"id":"CVE-2026-89726","state":"PUBLISHED","title":"lib/ucs2_string.c: fix out-of-bounds read in ucs2_strnlen()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nlib/ucs2_string.c: fix out-of-bounds read in ucs2_strnlen()\n\nPatch series \"lib/ucs2_string.c: fix out-of-bounds read in\nucs2_strnlen()\", v2.\n\nThis series fixes an off-by-one out-of-bounds read in ucs2_strnlen().\n\nThe first patch is the real fix, the second patch comes as a bonus and\nfixes the code indentation.\n\n\nThis patch (of 2):\n\nucs2_strnlen() checks the current character before checking whether the\ncaller-provided maximum length has been reached.  If the input is not\nNUL-terminated within that bound, the loop can read one ucs2_char_t past\nthe limit.\n\nTest the length before dereferencing to prevent an off-by-one\nout-of-bounds read.","publishedAt":"2026-09-11T19:46:37.480Z","updatedAt":"2026-10-19T08:51:39.437Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"04ae68af4107600120c3c41c94268f43bc350d48","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"2e5a70a175f0c74e7238b013a96c4eabc3002934","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"3ada20e110bf3245edb0a3bcddadc33d0f142f8d","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"60c74f42f5abddb85dd919b4448d5474e65dbe76","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"709eb41adaf78d59d4579a13a898125919b69bcc","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"7d658da725ea81c91f73087547b97e7ced82d62b","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"1b0dc3cbb8630f0b5cb34d848628225920a904be","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"cec0d03fe785380540dc1b4d07c80f67ae2ffc78","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["lib/ucs2_string.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.12","versionType":"semver"},{"version":"5.10.270","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.221","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.188","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.157","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.109","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.50","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.4","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["lib/ucs2_string.c"]}],"references":["https://git.kernel.org/stable/c/04ae68af4107600120c3c41c94268f43bc350d48","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/1b0dc3cbb8630f0b5cb34d848628225920a904be","https://git.kernel.org/stable/c/cec0d03fe785380540dc1b4d07c80f67ae2ffc78"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:26.108Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/89xxx/CVE-2026-89726.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-89726","state":"PUBLISHED","datePublished":"2026-09-11T19:46:37.480Z","dateUpdated":"2026-10-19T08:51:39.437Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-11T19:38:34.759Z"},"containers":{"cna":{"title":"lib/ucs2_string.c: fix out-of-bounds read in ucs2_strnlen()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nlib/ucs2_string.c: fix out-of-bounds read in ucs2_strnlen()\n\nPatch series \"lib/ucs2_string.c: fix out-of-bounds read in\nucs2_strnlen()\", v2.\n\nThis series fixes an off-by-one out-of-bounds read in ucs2_strnlen().\n\nThe first patch is the real fix, the second patch comes as a bonus and\nfixes the code indentation.\n\n\nThis patch (of 2):\n\nucs2_strnlen() checks the current character before checking whether the\ncaller-provided maximum length has been reached.  If the input is not\nNUL-terminated within that bound, the loop can read one ucs2_char_t past\nthe limit.\n\nTest the length before dereferencing to prevent an off-by-one\nout-of-bounds read."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"04ae68af4107600120c3c41c94268f43bc350d48","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"2e5a70a175f0c74e7238b013a96c4eabc3002934","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"3ada20e110bf3245edb0a3bcddadc33d0f142f8d","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"60c74f42f5abddb85dd919b4448d5474e65dbe76","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"709eb41adaf78d59d4579a13a898125919b69bcc","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"7d658da725ea81c91f73087547b97e7ced82d62b","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"1b0dc3cbb8630f0b5cb34d848628225920a904be","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"cec0d03fe785380540dc1b4d07c80f67ae2ffc78","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["lib/ucs2_string.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.12","versionType":"semver"},{"version":"5.10.270","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.221","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.188","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.157","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.109","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.50","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.4","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["lib/ucs2_string.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/04ae68af4107600120c3c41c94268f43bc350d48"},{"url":"https://git.kernel.org/stable/c/2e5a70a175f0c74e7238b013a96c4eabc3002934"},{"url":"https://git.kernel.org/stable/c/3ada20e110bf3245edb0a3bcddadc33d0f142f8d"},{"url":"https://git.kernel.org/stable/c/60c74f42f5abddb85dd919b4448d5474e65dbe76"},{"url":"https://git.kernel.org/stable/c/709eb41adaf78d59d4579a13a898125919b69bcc"},{"url":"https://git.kernel.org/stable/c/7d658da725ea81c91f73087547b97e7ced82d62b"},{"url":"https://git.kernel.org/stable/c/1b0dc3cbb8630f0b5cb34d848628225920a904be"},{"url":"https://git.kernel.org/stable/c/cec0d03fe785380540dc1b4d07c80f67ae2ffc78"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T08:51:39.437Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"5.10.270"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"5.15.221"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.1.188"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.6.157"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.12.109"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.18.50"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"7.2.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}