FKIE_CVE-2026-98600

Vulnerability from fkie_nvd - Published: 2026-10-18 16:17 - Updated: 2026-10-19 10:19
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
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6d91041bb38b97e2feb625123cc0529d7b83a0e1
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/71ccacde407b7d8f0ef48974a0d2524602fd5c44
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/76876fd26569302d26d91cbe8b75fa8e66cf8969
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/7a1781a2f3a9667b3065d402d1f11986a2363e08
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/9240fc1f2cde5331c61608da21b00394602ca762
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/97711b964877242933484989224a3c4c5d88a5ee
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/be00deee60044ffa820f9436415caeb665b2cda0
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c25587fa26761e623198b4f47151fe79d09ccde6
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "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"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "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)."
    }
  ],
  "id": "CVE-2026-98600",
  "lastModified": "2026-10-19T10:19:21.517",
  "metrics": {},
  "published": "2026-10-18T16:17:12.707",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6d91041bb38b97e2feb625123cc0529d7b83a0e1"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/71ccacde407b7d8f0ef48974a0d2524602fd5c44"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/76876fd26569302d26d91cbe8b75fa8e66cf8969"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/7a1781a2f3a9667b3065d402d1f11986a2363e08"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/9240fc1f2cde5331c61608da21b00394602ca762"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/97711b964877242933484989224a3c4c5d88a5ee"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/be00deee60044ffa820f9436415caeb665b2cda0"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c25587fa26761e623198b4f47151fe79d09ccde6"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.

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

Author Source Type Date Other

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.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • 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.
Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

JSON

Loading timeline…




    Related by attack behaviour

    Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.