CVE-2026-53256
What it is
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: RFCOMM: hold listener socket in rfcomm_connect_ind() rfcomm_get_sock_by_channel() scans rfcomm_sk_list under the list lock, but returns the selected listener after dropping that lock without taking a reference. rfcomm_connect_ind() then locks the listener, queues a child socket on it, and may notify it after unlocking it. The buggy scenario involves two paths, with each column showing the order within that path: rfcomm_connect_ind(): listener close: 1. Find parent in 1. close() enters rfcomm_get_sock_by_channel() rfcomm_sock_release(). 2. Drop rfcomm_sk_list.lock 2. rfcomm_sock_shutdown() without pinning parent. closes the listener. 3. Call lock_sock(parent) and 3. rfcomm_sock_kill() bt_accept_enqueue(parent, unlinks and puts parent. sk, true). 4. Read parent flags and may 4. parent can be freed. call sk_state_change(). If close wins the race, parent can be freed before rfcomm_connect_ind() reaches lock_sock(), bt_accept_enqueue(), or the deferred-setup callback. Take a reference on the listener before leaving rfcomm_sk_list.lock. After lock_sock() succeeds, recheck that it is still in BT_LISTEN before queueing a child, cache the deferred-setup bit while the parent is locked, and drop the reference after the last parent use. KASAN reported a slab-use-after-free in lock_sock_nested() from rfcomm_connect_ind(), with the freeing stack going through rfcomm_sock_kill() and rfcomm_sock_release().
At a glance
- Exploitability
- Can be exploited from the same network segment with a low-privilege account. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.3% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.3% in the next 30 days (EPSS).
- Severity: 8.0 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.3% · EPSS, next 30 days
- Weakness
- CWE-416 · Use after free
- Record status
- Modified
Affected
- Linux Kernel < 5.10.259
- Linux Kernel < 5.15.210
- Linux Kernel < 6.1.176
- Linux Kernel < 6.6.143
- Linux Kernel < 6.12.94
- Linux Kernel < 6.18.36
- Linux Kernel < 7.0.13
- Linux Kernel 2.6.12
Attack profile CVSS 3.1 · 8.0
- Attack vector
- Adjacent network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-53256.md and follow it. Check whether this project is affected by CVE-2026-53256. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/1f73f92f66251065a5f39b09a47cf05ea14d3107
- https://git.kernel.org/stable/c/43c441edacf953b39517a44f5e5e10a93618b226
- https://git.kernel.org/stable/c/6f4462d12133106460d7c046b95aad2491e3fddf
- https://git.kernel.org/stable/c/8802413ce63175fb522a2bd609fb043a3550c720
- https://git.kernel.org/stable/c/a07d741c077d4e34b16458241a94d29039386553
- https://git.kernel.org/stable/c/b0e33e409715c617e2a20f46f99aa5403a14dfda
- https://git.kernel.org/stable/c/de31973ef00e5aa55496f84cf6a44bb157a34e02
- https://git.kernel.org/stable/c/f5ec76bdbeb80f75ad0be204371afffee0f8fac8
References
- https://git.kernel.org/stable/c/1f73f92f66251065a5f39b09a47cf05ea14d3107
- https://git.kernel.org/stable/c/43c441edacf953b39517a44f5e5e10a93618b226
- https://git.kernel.org/stable/c/6f4462d12133106460d7c046b95aad2491e3fddf
- https://git.kernel.org/stable/c/8802413ce63175fb522a2bd609fb043a3550c720
- https://git.kernel.org/stable/c/a07d741c077d4e34b16458241a94d29039386553
- https://git.kernel.org/stable/c/b0e33e409715c617e2a20f46f99aa5403a14dfda
- https://git.kernel.org/stable/c/de31973ef00e5aa55496f84cf6a44bb157a34e02
- https://git.kernel.org/stable/c/f5ec76bdbeb80f75ad0be204371afffee0f8fac8
- https://cert-portal.siemens.com/productcert/html/ssa-784472.html