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CVE-2026-53276 (GCVE-0-2026-53276)

Vulnerability from cvelistv5 – Published: 2026-06-25 08:39 – Updated: 2026-08-05 12:34
VLAI
Title
Bluetooth: ISO: Fix a use-after-free of the hci_conn pointer
Summary
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: Fix a use-after-free of the hci_conn pointer In iso_sock_rebind_bc(), the bis pointer is cached, then the socket lock is dropped: bis = iso_pi(sk)->conn->hcon; /* Release the socket before lookups since that requires hci_dev_lock * which shall not be acquired while holding sock_lock for proper * ordering. */ release_sock(sk); hci_dev_lock(bis->hdev); During the unlocked window, could a concurrent close() destroy the connection and free the bis structure, causing hci_dev_lock(bis->hdev) to access memory after it is freed, fix this by using the hdev reference which was safely acquired via iso_conn_get_hdev().
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: d3413703d5f8b7d1e6f514f9440ed5da1bc30796 , < d324b8aa20bd3c3394e3647dc22491d88f3f4e7a (git)
Affected: d3413703d5f8b7d1e6f514f9440ed5da1bc30796 , < f50331f2a1441ec49988832c3a95f2edacc47322 (git)
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Linux Linux Affected: 6.19
Unaffected: 0 , < 6.19 (semver)
Unaffected: 7.0.13 , ≤ 7.0.* (semver)
Unaffected: 7.1 , ≤ * (original_commit_for_fix)
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{
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          "product": "Linux",
          "programFiles": [
            "net/bluetooth/iso.c"
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              "value": "AV:L - The vulnerable path is reached through local AF_BLUETOOTH ISO socket operations, specifically bind() rebinding on an already connected or CONNECT2 ISO socket. An adjacent Bluetooth peer may be involved in establishing BIS/PAST state, but the actual trigger is a local syscall/race, not an unauthenticated received packet alone.\nAC:L - The bug is a use-after-free race where the rebind path drops the socket lock and a concurrent close can free the cached hci_conn pointer. A local attacker can control both sides by using concurrent operations on their own socket, so no uncontrollable condition is required.\nPR:L - The ISO socket create/bind/connect/rebind path has no CAP_NET_ADMIN or CAP_NET_RAW check, but it requires the attacker to run local code and create/use a Bluetooth ISO socket. This is therefore basic unprivileged local access rather than real administrative privilege.\nUI:N - No victim user action is required once the attacker can run local code; the attacker can create the socket state and trigger the concurrent bind/close race themselves.\nS:U - The vulnerable code is in the kernel Bluetooth stack and impacts the same kernel security authority. There is no VM escape, IOMMU bypass, or other cross-scope boundary indicated.\nC:H - This is a use-after-free of an hci_conn pointer, and under the required higher-severity rule UAFs are treated as capable of enabling memory disclosure through heap reuse and object manipulation.\nI:H - A kernel use-after-free can potentially be shaped into control-flow or data-structure corruption via heap spraying/reuse. Under the required higher-severity rule, this supports high integrity impact.\nA:H - The stale hci_conn dereference can access freed memory while taking hci_dev_lock(bis-\u003ehdev), which can oops or panic the kernel. A repeatable local trigger gives high availability impact."
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    "dateReserved": "2026-06-09T07:44:35.395Z",
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    "redhat_vex": {
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      "cve": "CVE-2026-53276",
      "id": "CVE-2026-53276",
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      "cve": "CVE-2026-53276",
      "id": "CVE-2026-53276",
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      "product_status:known_not_affected": "293",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-53276",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-53276.json",
      "version": "5"
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}



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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.
  • 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.


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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.