CVE-2026-63975 (GCVE-0-2026-63975)

Vulnerability from cvelistv5 – Published: 2026-07-19 14:56 – Updated: 2026-08-05 12:37
VLAI
Title
Bluetooth: L2CAP: Fix possible crash on l2cap_ecred_conn_rsp
Summary
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix possible crash on l2cap_ecred_conn_rsp If dcid is received for an already-assigned destination CID the spec requires that both channels to be discarded, but calling l2cap_chan_del may invalidate the tmp cursor created by list_for_each_entry_safe and in fact it is the wrong procedure as the chan->dcid may be assigned previously it really needs to be disconnected. Calling l2cap_chan_clone directly may still lead to l2cap_chan_del so instead schedule l2cap_chan_timeout with delay 0 to close the channel asynchronously.
Severity
8.8 (High)
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 15f02b91056253e8cdc592888f431da0731337b8 , < 3c8eaa91eb433c450426539290be4ffe282e9f00 (git)
Affected: 15f02b91056253e8cdc592888f431da0731337b8 , < ecfed1e0d8efecad6737a0d83e21d2fd021d8c48 (git)
Affected: 15f02b91056253e8cdc592888f431da0731337b8 , < e6833e737a51db1e5ea0401322acf5e22abd8be6 (git)
Affected: 15f02b91056253e8cdc592888f431da0731337b8 , < 6319b38fe69f56ed95680ade485b957a53fff642 (git)
Affected: 15f02b91056253e8cdc592888f431da0731337b8 , < 291eec1041c918c460dc9702e44edd17794b4a4b (git)
Affected: 15f02b91056253e8cdc592888f431da0731337b8 , < 41e29548b5e8b5e5fcf708786b3bea67cab107fa (git)
Affected: 15f02b91056253e8cdc592888f431da0731337b8 , < d153b8898c0051eb8b6a083b35cbe304a5886bd5 (git)
Affected: 15f02b91056253e8cdc592888f431da0731337b8 , < 41c2713b204e6cb6a94587bc6bf6935107df5479 (git)
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Linux Linux Affected: 5.7
Unaffected: 0 , < 5.7 (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)
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              "value": "AV:A - The bug is reached when a remote Bluetooth LE peer sends a crafted L2CAP_ECRED_CONN_RSP on the LE signaling channel, processed via hci_recv_frame \u2192 l2cap_recv_acldata \u2192 l2cap_le_sig_channel \u2192 l2cap_ecred_conn_rsp. Bluetooth is Adjacent per kernel CVSS guidance.\nAC:L - An adjacent attacker who establishes a BLE ACL link can reliably trigger this by first creating an L2CAP channel with a chosen DCID (via ECRED_CONN_REQ SCIDs) and then sending a connection response reusing that DCID for a pending outgoing ECRED connection; no race or rare layout is required.\nPR:N - Exploitation requires only the ability to act as a remote Bluetooth peer on an established ACL connection; no local shell access, capabilities, or root on the victim system is needed.\nUI:N - The malicious signaling traffic is delivered entirely by the remote attacker once a BLE link exists; no additional victim-side file open, mount, or application action beyond normal Bluetooth connectivity is required to reach the vulnerable handler.\nS:U - The failure is a kernel L2CAP channel-list use-after-free and crash within the Bluetooth stack on the victim host; it does not cross a VM, container, or IOMMU security boundary.\nC:H - Calling l2cap_chan_del() on the original channel during list_for_each_entry_safe can free the saved tmp list node, causing a use-after-free on struct l2cap_chan when iteration continues; UAF is scored as High confidentiality impact.\nI:H - The same iterator invalidation frees and later dereferences l2cap_chan objects under attacker-influenced connection state, providing a heap UAF primitive that can be groomed toward arbitrary memory corruption and code execution.\nA:H - The bug reliably produces kernel list corruption and use-after-free in softirq/context Bluetooth receive path, leading to kernel oops or panic and denial of service on phones, laptops, and embedded devices with Bluetooth enabled."
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    "datePublished": "2026-07-19T14:56:00.662Z",
    "dateReserved": "2026-07-19T07:54:57.024Z",
    "dateUpdated": "2026-08-05T12:37:46.003Z",
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            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: L2CAP: Fix possible crash on l2cap_ecred_conn_rsp\n\nIf dcid is received for an already-assigned destination CID the spec\nrequires that both channels to be discarded, but calling l2cap_chan_del\nmay invalidate the tmp cursor created by list_for_each_entry_safe and\nin fact it is the wrong procedure as the chan-\u003edcid may be assigned\npreviously it really needs to be disconnected.\n\nCalling l2cap_chan_clone directly may still lead to l2cap_chan_del so\ninstead schedule l2cap_chan_timeout with delay 0 to close the channel\nasynchronously."
          }
        ],
        "id": "CVE-2026-63975",
        "lastModified": "2026-07-30T14:51:11.223",
        "metrics": {
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                "attackVector": "ADJACENT_NETWORK",
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                "baseScore": 8.8,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "HIGH",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
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        "published": "2026-07-19T16:17:16.603",
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          }
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        "vulnStatus": "Awaiting Analysis"
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      "current_release_date": "2026-09-14T11:48:12+00:00",
      "cve": "CVE-2026-63975",
      "id": "CVE-2026-63975",
      "initial_release_date": "2026-07-19T00:00:00+00:00",
      "product_status:fixed": "612",
      "product_status:known_affected": "70",
      "product_status:known_not_affected": "43",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: Bluetooth: L2CAP: Fix possible crash on l2cap_ecred_conn_rsp",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-63975.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "important",
      "current_release_date": "2026-09-18T00:45:29Z",
      "cve": "CVE-2026-63975",
      "id": "CVE-2026-63975",
      "initial_release_date": "2026-07-21T13:02:22Z",
      "product_status:first_fixed": "2",
      "product_status:known_affected": "428",
      "product_status:known_not_affected": "196",
      "product_status:recommended": "525",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-63975",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-63975.json",
      "version": "16"
    }
  }
}



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Tags
Taxonomy of the tags.





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.


Detection rules are retrieved from Rulezet.


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.