{"id":"CVE-2026-53357","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: fix UAF in l2cap_sock_cleanup_listen() vs l2cap_conn_del()\n\nbt_accept_dequeue() unlinks a not-yet-accepted child from the parent\naccept queue and release_soc…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: fix UAF in l2cap_sock_cleanup_listen() vs l2cap_conn_del()\n\nbt_accept_dequeue() unlinks a not-yet-accepted child from the parent\naccept queue and release_soc…","severity":"high","cvss":8,"cvssVector":"CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","published":"2026-07-02","updated":"2026-07-18","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-53357","references":[{"url":"https://git.kernel.org/stable/c/407217734835d21d4e0105ebf347860dc1806f88","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5d86d2f1b4d9a508c441d3e45277ae1a73cfed57","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/751de6ec671fe75ad9cf65a0638d2a06b6a5984d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/7eebd4c2c86f573af87ff165d08a83432eb0b919","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/87c543e2f78d0871f271df92dab98901bbd5b6f5","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a5ca86a6097a8b030ca3226cd300b17ed330f966","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ab1513597c6cf17cd1ad2a21e3b045421b48e022","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/added1213395071470a900cc845a042fb51882a6","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53357.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-53357"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2496574"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-53357"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53357"},{"url":"https://lore.kernel.org/linux-cve-announce/2026070234-CVE-2026-53357-18f1@gregkh/T"},{"url":"https://access.redhat.com/errata/RHSA-2026:76738"},{"url":"https://access.redhat.com/errata/RHSA-2026:76739"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"epss":0.00332,"epssPercentile":0.26265,"ingestedAt":"2026-07-18T13:23:33.223Z","vendor":"Linux","product":"Linux","affected":["Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < 751de6ec671fe75ad9cf65a0638d2a06b6a5984d","Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < 407217734835d21d4e0105ebf347860dc1806f88","Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < 7eebd4c2c86f573af87ff165d08a83432eb0b919","Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < 5d86d2f1b4d9a508c441d3e45277ae1a73cfed57","Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < 87c543e2f78d0871f271df92dab98901bbd5b6f5","Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < added1213395071470a900cc845a042fb51882a6","Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < a5ca86a6097a8b030ca3226cd300b17ed330f966","Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < ab1513597c6cf17cd1ad2a21e3b045421b48e022","Linux 5.7"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T15:28:47.902686Z"},"patched":["10base_smtv","enterprise_linux_appstream_v_10","enterprise_linux_appstream_v_9","enterprise_linux_baseos_v_10","enterprise_linux_baseos_v_9","enterprise_linux_codeready_linux_builder_v_10","enterprise_linux_codeready_linux_builder_v_9","enterprise_linux_hidden_v_10","enterprise_linux_real_time_for_nfv_v_10","enterprise_linux_real_time_for_nfv_v_9","enterprise_linux_real_time_v_10","enterprise_linux_real_time_v_9"],"cwe":["CWE-366"],"scores":{"nvd":8,"vendor":7},"slug":"CVE-2026-53357","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: fix UAF in l2cap_sock_cleanup_listen() vs l2cap_conn_del()\n\nbt_accept_dequeue() unlinks a not-yet-accepted child from the parent\naccept queue and release_sock()s it before returning, so the returned\nsk has no caller reference and is unlocked.\n\nl2cap_sock_cleanup_listen() walks these children on listening-socket\nclose.  A concurrent HCI disconnect drives hci_rx_work ->\nl2cap_conn_del() which runs l2cap_chan_del() + l2cap_sock_kill() and\nfrees the child sk and its l2cap_chan; cleanup_listen() then uses both:\n\n  BUG: KASAN: slab-use-after-free in l2cap_sock_kill\n    l2cap_sock_kill / l2cap_sock_cleanup_listen / __x64_sys_close\n  Freed by: l2cap_conn_del -> l2cap_sock_close_cb -> l2cap_sock_kill\n\nThis is distinct from the two fixes already in this area: commit\ne83f5e24da741 (\"Bluetooth: serialize accept_q access\") serialises the\naccept_q list/poll and takes temporary refs inside bt_accept_dequeue(),\nand CVE-2025-39860 serialises the userspace close()/accept() race by\ncalling cleanup_listen() under lock_sock() in l2cap_sock_release().\nNeither covers l2cap_conn_del() running from hci_rx_work, so this UAF\nstill reproduces on current bluetooth/master.\n\nTake the reference at the source: bt_accept_dequeue() does sock_hold()\nwhile sk is still locked, before release_sock(); callers sock_put().\ncleanup_listen() pins the chan with l2cap_chan_hold_unless_zero() under\na brief child sk lock (serialising vs l2cap_sock_teardown_cb()), drops\nit before l2cap_chan_lock(), and skips a duplicate l2cap_sock_kill() on\nSOCK_DEAD.  conn->lock is not taken here: cleanup_listen() runs under\nthe parent sk lock and that would invert\nconn->lock -> chan->lock -> sk_lock (lockdep).\n\nKASAN/SMP: an unprivileged listen/close vs HCI-disconnect race produced\n12 use-after-free reports per run before this change; 0, and no lockdep\nreport, over 1600+ raced iterations after it on bluetooth/master.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **RHSA-2026:76738** · Red Hat · fixed in: 10Base-SMTV, Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10), Red Hat Enterprise Linux Hidden (v. 10), Red Hat Enterprise Linux Real Time for NFV (v. 10), … · released 2026-10-08 · [advisory](https://access.redhat.com/errata/RHSA-2026:76738)\n- **RHSA-2026:76739** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9), Red Hat Enterprise Linux Real Time for NFV (v. 9), Red Hat Enterprise Linux Real Time (v. 9) · released 2026-10-08 · [advisory](https://access.redhat.com/errata/RHSA-2026:76739)\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · updated 2026-10-26 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53357.json)","depth":"twilight","depthScore":44,"depthScoreParts":{"impact":44,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}