CVE-2026-72333 (GCVE-0-2026-72333)
Vulnerability from cvelistv5
Published
2026-08-15 05:55
Modified
2026-08-17 05:12
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: fix tx ident leak for commands without a response Commit 6c3ea155e5ee ("Bluetooth: L2CAP: Fix not tracking outstanding TX ident") changed ident allocation to use an IDA, releasing idents in l2cap_put_ident() when the matching response command is received. But identifiers allocated for commands that have no response defined are never released. In particular L2CAP_LE_CREDITS is sent repeatedly for the lifetime of an LE CoC channel, so a peer streaming data to the host exhausts the 1-255 ident range after 254 credit packets. From then on l2cap_get_ident() fails: kernel: Bluetooth: Unable to allocate ident: -28 and every subsequent L2CAP_LE_CREDITS packet is sent with ident 0, which is invalid (Core Spec, Vol 3, Part A, Section 4: "Signaling identifier 0x00 is an invalid identifier and shall never be used in any command"). Remote stacks that validate the ident drop these commands, never receive new credits, and the channel stalls permanently. With default socket buffers this happens after roughly 0.5 MB of received data (the exact amount depends on the socket receive buffer): < ACL Data TX: Handle 2048 flags 0x00 dlen 12 LE L2CAP: LE Flow Control Credit (0x16) ident 0 len 4 Source CID: 64 Credits: 1 Release the ident immediately after sending L2CAP_LE_CREDITS since no response will ever release it. Use a local variable instead of chan->ident so that an ident that an EXT_FLOWCTL channel may be waiting on (e.g. a pending reconfigure) is not overwritten by a credit packet. Also add the missing L2CAP_LE_CONN_RSP case to l2cap_put_ident() so idents allocated for outgoing L2CAP_LE_CONN_REQ commands are released when the response arrives.
References
Impacted products
Vendor Product Version
Linux Linux Version: e86554c37d3d2b4b24608e0313f882cae28b8adb
Version: 9b24ad4787cad46a3917620799f8455c6533b8df
Version: ea6cf86167b3972caa68972d2a1ad43ecbbb8331
Version: 6c3ea155e5ee3e56606233acde8309afda66d483
Version: 6c3ea155e5ee3e56606233acde8309afda66d483
Version: ed97bb2cf96684ee646be6f37e4c4835f9d30caa
Version: 84bc3197f7d87c5b89c156e853d0561a9154eceb
Version: 8c1cdbc1bacc0cf9c27c3ebda11a81c3dcd01630
Version: 6.18.21   ≤
Version: 5.10.261   ≤
Version: 5.15.212   ≤
Version: 6.19.11   ≤
Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/bluetooth/l2cap_core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "b8a32a5fc915b024c60f18d51b6cffd2bd64d4a6",
              "status": "affected",
              "version": "e86554c37d3d2b4b24608e0313f882cae28b8adb",
              "versionType": "git"
            },
            {
              "lessThan": "bd1e01170341291292fd4c46b5f6949da282ca6c",
              "status": "affected",
              "version": "9b24ad4787cad46a3917620799f8455c6533b8df",
              "versionType": "git"
            },
            {
              "lessThan": "0c602cb8f148a36bfb39c25ade400bdadc023c4f",
              "status": "affected",
              "version": "ea6cf86167b3972caa68972d2a1ad43ecbbb8331",
              "versionType": "git"
            },
            {
              "lessThan": "d0a2b0c81f112540a337cde1c20251bf05ddf1da",
              "status": "affected",
              "version": "6c3ea155e5ee3e56606233acde8309afda66d483",
              "versionType": "git"
            },
            {
              "lessThan": "6e1930ece855a4c256f1c7e6632d634cfb9888b5",
              "status": "affected",
              "version": "6c3ea155e5ee3e56606233acde8309afda66d483",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "ed97bb2cf96684ee646be6f37e4c4835f9d30caa",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "84bc3197f7d87c5b89c156e853d0561a9154eceb",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "8c1cdbc1bacc0cf9c27c3ebda11a81c3dcd01630",
              "versionType": "git"
            },
            {
              "lessThan": "6.18.40",
              "status": "affected",
              "version": "6.18.21",
              "versionType": "semver"
            },
            {
              "lessThan": "5.11",
              "status": "affected",
              "version": "5.10.261",
              "versionType": "semver"
            },
            {
              "lessThan": "5.16",
              "status": "affected",
              "version": "5.15.212",
              "versionType": "semver"
            },
            {
              "lessThan": "6.20",
              "status": "affected",
              "version": "6.19.11",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/bluetooth/l2cap_core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "7.0"
            },
            {
              "lessThan": "7.0",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.40",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.40",
                  "versionStartIncluding": "6.18.21",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.5",
                  "versionStartIncluding": "7.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "7.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "5.10.261",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "5.15.212",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "6.19.11",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: L2CAP: fix tx ident leak for commands without a response\n\nCommit 6c3ea155e5ee (\"Bluetooth: L2CAP: Fix not tracking outstanding\nTX ident\") changed ident allocation to use an IDA, releasing idents in\nl2cap_put_ident() when the matching response command is received.\n\nBut identifiers allocated for commands that have no response defined\nare never released. In particular L2CAP_LE_CREDITS is sent repeatedly for\nthe lifetime of an LE CoC channel, so a peer streaming data to the\nhost exhausts the 1-255 ident range after 254 credit packets. From\nthen on l2cap_get_ident() fails:\n\n    kernel: Bluetooth: Unable to allocate ident: -28\n\nand every subsequent L2CAP_LE_CREDITS packet is sent with ident 0,\nwhich is invalid (Core Spec, Vol 3, Part A, Section 4: \"Signaling\nidentifier 0x00 is an invalid identifier and shall never be used in\nany command\"). Remote stacks that validate the ident drop these\ncommands, never receive new credits, and the channel stalls\npermanently. With default socket buffers this happens after roughly 0.5 MB\nof received data (the exact amount depends on the socket receive buffer):\n\n  \u003c ACL Data TX: Handle 2048 flags 0x00 dlen 12\n        LE L2CAP: LE Flow Control Credit (0x16) ident 0 len 4\n          Source CID: 64\n          Credits: 1\n\nRelease the ident immediately after sending L2CAP_LE_CREDITS since no\nresponse will ever release it. Use a local variable instead of\nchan-\u003eident so that an ident that an EXT_FLOWCTL channel may be waiting on\n(e.g. a pending reconfigure) is not overwritten by a credit packet.\n\nAlso add the missing L2CAP_LE_CONN_RSP case to l2cap_put_ident() so\nidents allocated for outgoing L2CAP_LE_CONN_REQ commands are released\nwhen the response arrives."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:12:40.473Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/b8a32a5fc915b024c60f18d51b6cffd2bd64d4a6"
        },
        {
          "url": "https://git.kernel.org/stable/c/bd1e01170341291292fd4c46b5f6949da282ca6c"
        },
        {
          "url": "https://git.kernel.org/stable/c/0c602cb8f148a36bfb39c25ade400bdadc023c4f"
        },
        {
          "url": "https://git.kernel.org/stable/c/d0a2b0c81f112540a337cde1c20251bf05ddf1da"
        },
        {
          "url": "https://git.kernel.org/stable/c/6e1930ece855a4c256f1c7e6632d634cfb9888b5"
        }
      ],
      "title": "Bluetooth: L2CAP: fix tx ident leak for commands without a response",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-72333",
    "datePublished": "2026-08-15T05:55:42.523Z",
    "dateReserved": "2026-08-09T03:40:39.920Z",
    "dateUpdated": "2026-08-17T05:12:40.473Z",
    "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.