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VulnerabilityPublished Updated

CVE-2026-63946: Linux kernel · Bluetooth: ISO: fix UAF in iso_recv_frame

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 8.8 High · fixed in c318aa51830a3d2cc1229968fe521441c97356cd : patch Linux kernel soon.

Data as of 26 Oct 2026, 13:47 UTC

CVSS 3.1 base score
8.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.3% chance of exploitation in 30 days – higher than 26% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in c318aa51830a3d2cc1229968fe521441c97356cd, c57ea90f203c8b8b41a474f19a09000d0f841436, b04ec131325baf4ea4577d6c6e6b86cf092e3731 +3
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 19 Jul 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ ccf74f2390d60a2f9a75ef496d2564abb478f46a, < c318aa51830a3d2cc1229968fe521441c97356cd
Fixed in
  • c318aa51830a3d2cc1229968fe521441c97356cd
LinuxLinuxAffected
  • ≥ ccf74f2390d60a2f9a75ef496d2564abb478f46a, < c57ea90f203c8b8b41a474f19a09000d0f841436
Fixed in
  • c57ea90f203c8b8b41a474f19a09000d0f841436
LinuxLinuxAffected
  • ≥ ccf74f2390d60a2f9a75ef496d2564abb478f46a, < b04ec131325baf4ea4577d6c6e6b86cf092e3731
Fixed in
  • b04ec131325baf4ea4577d6c6e6b86cf092e3731
LinuxLinuxAffected
  • ≥ ccf74f2390d60a2f9a75ef496d2564abb478f46a, < 119fb6f80c44dc1c65d604cf28e64c56bd9b6568
Fixed in
  • 119fb6f80c44dc1c65d604cf28e64c56bd9b6568
LinuxLinuxAffected
  • ≥ ccf74f2390d60a2f9a75ef496d2564abb478f46a, < 47f23a259517abbdb8032c057a1e8a6bf3734878
Fixed in
  • 47f23a259517abbdb8032c057a1e8a6bf3734878
LinuxLinuxAffected
  • ≥ ccf74f2390d60a2f9a75ef496d2564abb478f46a, < 1a6b803b00ccdd7666506adbe01ddae1c72d1ca9
Fixed in
  • 1a6b803b00ccdd7666506adbe01ddae1c72d1ca9

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: fix UAF in iso_recv_frame iso_recv_frame reads conn->sk under iso_conn_lock but releases the lock before using sk, with no reference held. A concurrent iso_sock_kill() can free sk in that window, causing use-after-free on sk->sk_state and sock_queue_rcv_skb(). Fix by replacing the bare pointer read with iso_sock_hold(conn), which calls sock_hold() while the spinlock is held, atomically elevating the refcount before the lock drops. Add a drop_put label so sock_put() is called on all exit paths where the hold succeeded.

References

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