CVE-2026-89726 (GCVE-0-2026-89726)

Vulnerability from cvelistv5 – Published: 2026-09-11 19:46 – Updated: 2026-10-19 08:51
VLAI
Title
lib/ucs2_string.c: fix out-of-bounds read in ucs2_strnlen()
Summary
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.
Severity
No CVSS data available.
Assigner
Linux CNA under the mitre root
CNA scorecard D 53/100 over 7018 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 04ae68af4107600120c3c41c94268f43bc350d48 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 2e5a70a175f0c74e7238b013a96c4eabc3002934 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 3ada20e110bf3245edb0a3bcddadc33d0f142f8d (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 60c74f42f5abddb85dd919b4448d5474e65dbe76 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 709eb41adaf78d59d4579a13a898125919b69bcc (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 7d658da725ea81c91f73087547b97e7ced82d62b (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 1b0dc3cbb8630f0b5cb34d848628225920a904be (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < cec0d03fe785380540dc1b4d07c80f67ae2ffc78 (git)
guessed Create a notification for this product.
Linux Linux Affected: 2.6.12
Unaffected: 0 , < 2.6.12 (semver)
Unaffected: 5.10.270 , ≤ 5.10.* (semver)
Unaffected: 5.15.221 , ≤ 5.15.* (semver)
Unaffected: 6.1.188 , ≤ 6.1.* (semver)
Unaffected: 6.6.157 , ≤ 6.6.* (semver)
Unaffected: 6.12.109 , ≤ 6.12.* (semver)
Unaffected: 6.18.50 , ≤ 6.18.* (semver)
Unaffected: 7.2.4 , ≤ 7.2.* (semver)
Unaffected: 7.3 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website
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      "descriptions": [
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          "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."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-19T08:51:39.437Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
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          "url": "https://git.kernel.org/stable/c/04ae68af4107600120c3c41c94268f43bc350d48"
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          "url": "https://git.kernel.org/stable/c/2e5a70a175f0c74e7238b013a96c4eabc3002934"
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        {
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      "title": "lib/ucs2_string.c: fix out-of-bounds read in ucs2_strnlen()",
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89726",
    "datePublished": "2026-09-11T19:46:37.480Z",
    "dateReserved": "2026-09-11T19:38:34.759Z",
    "dateUpdated": "2026-10-19T08:51:39.437Z",
    "state": "PUBLISHED"
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      "date": "2026-11-01",
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      "id": "msrc_CVE-2026-89726",
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      "product_status:fixed": "1",
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      "source": "Microsoft CSAF VEX",
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      "title": "lib/ucs2_string.c: fix out-of-bounds read in ucs2_strnlen()",
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          }
        ],
        "id": "CVE-2026-89726",
        "lastModified": "2026-10-19T09:18:14.097",
        "metrics": {},
        "published": "2026-09-11T20:20:02.907",
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        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Received"
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    },
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-10-17T21:22:10+00:00",
      "cve": "CVE-2026-89726",
      "id": "CVE-2026-89726",
      "initial_release_date": "2026-09-11T00:00:00+00:00",
      "product_status:known_affected": "263",
      "product_status:known_not_affected": "14",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: lib/ucs2_string.c: fix out-of-bounds read in ucs2_strnlen()",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89726.json",
      "version": "3"
    }
  }
}



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