CVE-2026-63964 (GCVE-0-2026-63964)

Vulnerability from cvelistv5 – Published: 2026-07-19 14:55 – Updated: 2026-07-20 06:41
VLAI
Title
usb: typec: ucsi: ccg: reject firmware images without a ':' record header
Summary
In the Linux kernel, the following vulnerability has been resolved: usb: typec: ucsi: ccg: reject firmware images without a ':' record header do_flash() locates the first .cyacd record with p = strnchr(fw->data, fw->size, ':'); while (p < eof) { s = strnchr(p + 1, eof - p - 1, ':'); ... } If the firmware image contains no ':' byte, strnchr() returns NULL. NULL compares less than the valid kernel pointer eof, so the loop body runs and strnchr() is called with p + 1 == (void *)1 and a length of roughly (unsigned long)eof, causing a wonderful crash. The not_signed_fw fallthrough earlier in do_flash() and the chip-state branches in ccg_fw_update_needed() allow an unsigned blob to reach this loop, so a root user who can place a crafted file under /lib/firmware and write the do_flash sysfs attribute can trigger the oops. Bail out with -EINVAL when the initial strnchr() returns NULL.
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 5c9ae5a87573d38cfc4c740aafda2fa6ce06e401 , < b41dfc033fe594e152648050e95b9489cd53e9e3 (git)
Affected: 5c9ae5a87573d38cfc4c740aafda2fa6ce06e401 , < 2f395ca1263bd181995eb829f5943a83a20db213 (git)
Affected: 5c9ae5a87573d38cfc4c740aafda2fa6ce06e401 , < 6526f8684f72391138353642af908803ba70795e (git)
Affected: 5c9ae5a87573d38cfc4c740aafda2fa6ce06e401 , < 3f432b8203066c26770fe6ea591361f10021dd6b (git)
Affected: 5c9ae5a87573d38cfc4c740aafda2fa6ce06e401 , < c4ee519b06389e59ba2d6aa722fcc4a02a8bbcbb (git)
Affected: 5c9ae5a87573d38cfc4c740aafda2fa6ce06e401 , < a38ed87818b2419090fb1a6338ddce6842b65dfa (git)
Affected: 5c9ae5a87573d38cfc4c740aafda2fa6ce06e401 , < c8460de584fe5415d212cfdd127d4db90835a450 (git)
Affected: 5c9ae5a87573d38cfc4c740aafda2fa6ce06e401 , < d7486952bf74e546ee3748fb14b2d07881fa6273 (git)
Create a notification for this product.
Linux Linux Affected: 5.2
Unaffected: 0 , < 5.2 (semver)
Unaffected: 5.10.259 , ≤ 5.10.* (semver)
Unaffected: 5.15.210 , ≤ 5.15.* (semver)
Unaffected: 6.1.176 , ≤ 6.1.* (semver)
Unaffected: 6.6.143 , ≤ 6.6.* (semver)
Unaffected: 6.12.93 , ≤ 6.12.* (semver)
Unaffected: 6.18.35 , ≤ 6.18.* (semver)
Unaffected: 7.0.12 , ≤ 7.0.* (semver)
Unaffected: 7.1 , ≤ * (original_commit_for_fix)
Create a notification for this product.
Show details on NVD website
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{
  "containers": {
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              "version": "7.1",
              "versionType": "original_commit_for_fix"
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                  "versionStartIncluding": "5.2",
                  "vulnerable": true
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                  "versionEndExcluding": "5.15.210",
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      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nusb: typec: ucsi: ccg: reject firmware images without a \u0027:\u0027 record header\n\ndo_flash() locates the first .cyacd record with\n\n\tp = strnchr(fw-\u003edata, fw-\u003esize, \u0027:\u0027);\n\twhile (p \u003c eof) {\n\t\ts = strnchr(p + 1, eof - p - 1, \u0027:\u0027);\n\t\t...\n\t}\n\nIf the firmware image contains no \u0027:\u0027 byte,  strnchr() returns NULL.\nNULL compares less than the valid kernel pointer eof, so the loop body\nruns and strnchr() is called with p + 1 == (void *)1 and a length of\nroughly (unsigned long)eof, causing a wonderful crash.\n\nThe not_signed_fw fallthrough earlier in do_flash() and the chip-state\nbranches in ccg_fw_update_needed() allow an unsigned blob to reach this\nloop, so a root user who can place a crafted file under /lib/firmware\nand write the do_flash sysfs attribute can trigger the oops.\n\nBail out with -EINVAL when the initial strnchr() returns NULL."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-20T06:41:45.132Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
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          "url": "https://git.kernel.org/stable/c/b41dfc033fe594e152648050e95b9489cd53e9e3"
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          "url": "https://git.kernel.org/stable/c/2f395ca1263bd181995eb829f5943a83a20db213"
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        },
        {
          "url": "https://git.kernel.org/stable/c/d7486952bf74e546ee3748fb14b2d07881fa6273"
        }
      ],
      "title": "usb: typec: ucsi: ccg: reject firmware images without a \u0027:\u0027 record header",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
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    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-63964",
    "datePublished": "2026-07-19T14:55:53.115Z",
    "dateReserved": "2026-07-19T07:54:57.024Z",
    "dateUpdated": "2026-07-20T06:41:45.132Z",
    "state": "PUBLISHED"
  },
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      "date": "2026-07-21",
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      "cve": "CVE-2026-63964",
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      "product_status:known_affected": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "usb: typec: ucsi: ccg: reject firmware images without a \u0027:\u0027 record header",
      "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-63964.json",
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do_flash() and the chip-state\\nbranches in ccg_fw_update_needed() allow an unsigned blob to reach this\\nloop, so a root user who can place a crafted file under /lib/firmware\\nand write the do_flash sysfs attribute can trigger the oops.\\n\\nBail out with -EINVAL when the initial strnchr() returns NULL.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"drivers/usb/typec/ucsi/ucsi_ccg.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"5c9ae5a87573d38cfc4c740aafda2fa6ce06e401\",\"lessThan\":\"b41dfc033fe594e152648050e95b9489cd53e9e3\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"5c9ae5a87573d38cfc4c740aafda2fa6ce06e401\",\"lessThan\":\"2f395ca1263bd181995eb829f5943a83a20db213\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"5c9ae5a87573d38cfc4c740aafda2fa6ce06e401\",\"lessThan\":\"6526f8684f72391138353642af908803ba70795e\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"5c9ae5a87573d38cfc4c740aafda2fa6ce06e401\",\"lessThan\":\"3f432b8203066c26770fe6ea591361f10021dd6b\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"5c9ae5a87573d38cfc4c740aafda2fa6ce06e401\",\"lessThan\":\"c4ee519b06389e59ba2d6aa722fcc4a02a8bbcbb\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"5c9ae5a87573d38cfc4c740aafda2fa6ce06e401\",\"lessThan\":\"a38ed87818b2419090fb1a6338ddce6842b65dfa\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"5c9ae5a87573d38cfc4c740aafda2fa6ce06e401\",\"lessThan\":\"c8460de584fe5415d212cfdd127d4db90835a450\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"5c9ae5a87573d38cfc4c740aafda2fa6ce06e401\",\"lessThan\":\"d7486952bf74e546ee3748fb14b2d07881fa6273\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"drivers/usb/typec/ucsi/ucsi_ccg.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"5.2\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"5.2\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.10.259\",\"lessThanOrEqual\":\"5.10.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.15.210\",\"lessThanOrEqual\":\"5.15.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.1.176\",\"lessThanOrEqual\":\"6.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.143\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.93\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.35\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.0.12\",\"lessThanOrEqual\":\"7.0.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/2f395ca1263bd181995eb829f5943a83a20db213\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/3f432b8203066c26770fe6ea591361f10021dd6b\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/6526f8684f72391138353642af908803ba70795e\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/a38ed87818b2419090fb1a6338ddce6842b65dfa\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/b41dfc033fe594e152648050e95b9489cd53e9e3\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/c4ee519b06389e59ba2d6aa722fcc4a02a8bbcbb\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/c8460de584fe5415d212cfdd127d4db90835a450\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/d7486952bf74e546ee3748fb14b2d07881fa6273\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Low",
      "current_release_date": "2026-07-21T17:00:28+00:00",
      "cve": "CVE-2026-63964",
      "id": "CVE-2026-63964",
      "initial_release_date": "2026-07-19T00:00:00+00:00",
      "product_status:known_affected": "184",
      "product_status:known_not_affected": "90",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: usb: typec: ucsi: ccg: reject firmware images without a \u0027:\u0027 record header",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-63964.json",
      "version": "3"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.