CVE-2026-98600 (GCVE-0-2026-98600)
Vulnerability from cvelistv5
Published
2026-10-18 15:19
Modified
2026-10-19 09:22
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: RFCOMM: Reject short EA=0 frames in rfcomm_recv_frame() While rfcomm_recv_frame() verifies that skb->len is at least sizeof(*hdr) + 1 (4 bytes: 3-byte header + 1-byte FCS), an RFCOMM frame with an extended 2-byte length field (!__test_ea(hdr->len)) has a 4-byte header plus a 1-byte FCS (5 bytes minimum, sizeof(*hdr) + 2). When a 4-byte RFCOMM frame with EA == 0 arrives: 1. The initial skb->len < sizeof(*hdr) + 1 check passes (4 < 4 is false). 2. Trimming the FCS byte decrements skb->len to 3. 3. If __check_fcs() succeeds, skb_pull(skb, 4) fails (4 > 3) and returns NULL without advancing skb->data. 4. Because the return value of skb_pull() is ignored, the un-pulled 3-byte struct rfcomm_hdr remains at skb->data and is either queued as application payload via rfcomm_recv_data() or parsed as a multiplexer control command via rfcomm_recv_mcc() on DLCI 0. Fix this by extending the length check in rfcomm_recv_frame() to also require skb->len >= sizeof(*hdr) + 2 when !__test_ea(hdr->len).
References
Impacted products
Vendor Product Version
Linux Linux Version: fb40eda15122f6b780228639c1ead6820340ff54
Version: 3829af5fab5a22405bf1e7d69068c2ec0fce46ca
Version: b161eacd7fa4a2d765724b5504ac6cc388e48f80
Version: 30d1d9f3495463f7c026e4c553127f79b486fcd6
Version: 67dc3b40fae71b6b11c71e7ff69bac0758818c05
Version: bbc310caa2b6bf5fe42896ba27da0fbc12e4ac51
Version: b230e5bf501c5edaf2eb0991cb862ac142031d4b
Version: b230e5bf501c5edaf2eb0991cb862ac142031d4b
Version: 6.12.111   ≤
Version: 6.18.53   ≤
Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/bluetooth/rfcomm/core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "76876fd26569302d26d91cbe8b75fa8e66cf8969",
              "status": "affected",
              "version": "fb40eda15122f6b780228639c1ead6820340ff54",
              "versionType": "git"
            },
            {
              "lessThan": "97711b964877242933484989224a3c4c5d88a5ee",
              "status": "affected",
              "version": "3829af5fab5a22405bf1e7d69068c2ec0fce46ca",
              "versionType": "git"
            },
            {
              "lessThan": "7a1781a2f3a9667b3065d402d1f11986a2363e08",
              "status": "affected",
              "version": "b161eacd7fa4a2d765724b5504ac6cc388e48f80",
              "versionType": "git"
            },
            {
              "lessThan": "c25587fa26761e623198b4f47151fe79d09ccde6",
              "status": "affected",
              "version": "30d1d9f3495463f7c026e4c553127f79b486fcd6",
              "versionType": "git"
            },
            {
              "lessThan": "71ccacde407b7d8f0ef48974a0d2524602fd5c44",
              "status": "affected",
              "version": "67dc3b40fae71b6b11c71e7ff69bac0758818c05",
              "versionType": "git"
            },
            {
              "lessThan": "be00deee60044ffa820f9436415caeb665b2cda0",
              "status": "affected",
              "version": "bbc310caa2b6bf5fe42896ba27da0fbc12e4ac51",
              "versionType": "git"
            },
            {
              "lessThan": "9240fc1f2cde5331c61608da21b00394602ca762",
              "status": "affected",
              "version": "b230e5bf501c5edaf2eb0991cb862ac142031d4b",
              "versionType": "git"
            },
            {
              "lessThan": "6d91041bb38b97e2feb625123cc0529d7b83a0e1",
              "status": "affected",
              "version": "b230e5bf501c5edaf2eb0991cb862ac142031d4b",
              "versionType": "git"
            },
            {
              "lessThan": "6.12.112",
              "status": "affected",
              "version": "6.12.111",
              "versionType": "semver"
            },
            {
              "lessThan": "6.18.55",
              "status": "affected",
              "version": "6.18.53",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/bluetooth/rfcomm/core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "7.2"
            },
            {
              "lessThan": "7.2",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.112",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.55",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.9",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.112",
                  "versionStartIncluding": "6.12.111",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.55",
                  "versionStartIncluding": "6.18.53",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.9",
                  "versionStartIncluding": "7.2",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "7.2",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: RFCOMM: Reject short EA=0 frames in rfcomm_recv_frame()\n\nWhile rfcomm_recv_frame() verifies that skb-\u003elen is at least\nsizeof(*hdr) + 1 (4 bytes: 3-byte header + 1-byte FCS), an RFCOMM frame\nwith an extended 2-byte length field (!__test_ea(hdr-\u003elen)) has a 4-byte\nheader plus a 1-byte FCS (5 bytes minimum, sizeof(*hdr) + 2).\n\nWhen a 4-byte RFCOMM frame with EA == 0 arrives:\n1. The initial skb-\u003elen \u003c sizeof(*hdr) + 1 check passes (4 \u003c 4 is false).\n2. Trimming the FCS byte decrements skb-\u003elen to 3.\n3. If __check_fcs() succeeds, skb_pull(skb, 4) fails (4 \u003e 3) and returns\n   NULL without advancing skb-\u003edata.\n4. Because the return value of skb_pull() is ignored, the un-pulled\n   3-byte struct rfcomm_hdr remains at skb-\u003edata and is either queued as\n   application payload via rfcomm_recv_data() or parsed as a multiplexer\n   control command via rfcomm_recv_mcc() on DLCI 0.\n\nFix this by extending the length check in rfcomm_recv_frame() to also\nrequire skb-\u003elen \u003e= sizeof(*hdr) + 2 when !__test_ea(hdr-\u003elen)."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-19T09:22:26.711Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/76876fd26569302d26d91cbe8b75fa8e66cf8969"
        },
        {
          "url": "https://git.kernel.org/stable/c/97711b964877242933484989224a3c4c5d88a5ee"
        },
        {
          "url": "https://git.kernel.org/stable/c/7a1781a2f3a9667b3065d402d1f11986a2363e08"
        },
        {
          "url": "https://git.kernel.org/stable/c/c25587fa26761e623198b4f47151fe79d09ccde6"
        },
        {
          "url": "https://git.kernel.org/stable/c/71ccacde407b7d8f0ef48974a0d2524602fd5c44"
        },
        {
          "url": "https://git.kernel.org/stable/c/be00deee60044ffa820f9436415caeb665b2cda0"
        },
        {
          "url": "https://git.kernel.org/stable/c/9240fc1f2cde5331c61608da21b00394602ca762"
        },
        {
          "url": "https://git.kernel.org/stable/c/6d91041bb38b97e2feb625123cc0529d7b83a0e1"
        }
      ],
      "title": "Bluetooth: RFCOMM: Reject short EA=0 frames in rfcomm_recv_frame()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-98600",
    "datePublished": "2026-10-18T15:19:12.864Z",
    "dateReserved": "2026-09-25T10:25:14.359Z",
    "dateUpdated": "2026-10-19T09:22:26.711Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.