CVE-2026-31408
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Description
A flaw was found in the Linux kernel's Bluetooth SCO (Synchronous Connection-Oriented) protocol implementation. The sco_recv_frame() function fails to properly hold a reference to a socket after releasing a lock. This oversight allows a concurrent operation to free the socket while it is still being accessed, leading to a use-after-free vulnerability. A local attacker could potentially exploit this to cause memory corruption or a denial of service.
Statement
Under sco_conn_lock, the code read conn->sk then dropped the lock without sco_sock_hold(), so close() could race and free the socket before sk->sk_state use. The fix mirrors other SCO helpers. Adjacent Bluetooth is involved; impact is UAF and likely crash.
Additional information
- This content is not included.Bugzilla 2455334: kernel: Bluetooth: SCO: Fix use-after-free in sco_recv_frame() due to missing sock_hold
- Content from cwe.mitre.org is not included.CWE-911: Improper Update of Reference Count
Affected Packages and Issued Red Hat Security Errata
Unless explicitly stated as not affected, all previous versions of packages in any minor update stream of a product listed here should be assumed vulnerable, although may not have been subject to full analysis.
| Products / Services | Components | State | Errata |
|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Fixed | RHSA-2026:19569 |
| Red Hat Enterprise Linux 10.0 Extended Update Support | kernel | Fixed | RHSA-2026:39371 |
| Red Hat Enterprise Linux 6 | kernel | Out of support scope | |
| Red Hat Enterprise Linux 7 | kernel | Affected | |
| Red Hat Enterprise Linux 7 | kernel-rt | Affected | |
| Red Hat Enterprise Linux 8 | kernel | Fixed | RHSA-2026:21706 |
| Red Hat Enterprise Linux 8 | kernel-rt | Fixed | RHSA-2026:21745 |
| Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support | kernel | Fixed | RHSA-2026:35896 |
| Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On | kernel | Fixed | RHSA-2026:35896 |
| Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support | kernel | Fixed | RHSA-2026:35894 |
| Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On | kernel | Fixed | RHSA-2026:35894 |
| Red Hat Enterprise Linux 8.8 Telecommunications Update Service | kernel | Fixed | RHSA-2026:40760 |
| Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions | kernel | Fixed | RHSA-2026:40760 |
| Red Hat Enterprise Linux 9 | kernel-rt | Affected | |
| Red Hat Enterprise Linux 9 | kernel | Fixed | RHSA-2026:21556 |
| Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions | kernel-rt | Fixed | RHSA-2026:35904 |
| Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions | kernel | Fixed | RHSA-2026:36073 |
| Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions | kernel | Fixed | RHSA-2026:36767 |
| Red Hat Enterprise Linux 9.6 Extended Update Support | kernel | Fixed | RHSA-2026:38902 |
Common Vulnerability Scoring System (CVSS) Score Details
Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authorities (CNA) source for its products and services (see Red Hat classifications ).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| CVSS v3 Base Score | 7 | N/A | 8.8 |
| Attack Vector | Local | N/A | Adjacent Network |
| Attack Complexity | High | N/A | Low |
| Privileges Required | Low | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality Impact | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
CVSS v3 Vector
Red Hat CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
cve.org CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Frequently Asked Questions
Why is Red Hat's CVSS v3 score or Impact different from other vendors?
For more information, see https://access.redhat.com/solutions/762393.
My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?
- "Under investigation" doesn't necessarily mean that the product is affected by this vulnerability. It only means that our Analysis Team is still working on determining whether the product is affected and how it is affected.
- "Affected" means that our Analysis Team has determined that this product is affected by this vulnerability and might release a fix to address this in the near future.
What can I do if my product is listed as "Will not fix"?
Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
- Upgrade to a supported product version that includes a fix for this vulnerability (recommended).
- Apply a mitigation (if one exists).
- Open a This content is not included.support case to request a prioritization of releasing a fix for this vulnerability.
What can I do if my product is listed as "Fix deferred"?
Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
- Apply a mitigation (if one exists).
- Open a This content is not included.support case to request a prioritization of releasing a fix for this vulnerability.
- Red Hat Engineering focuses on addressing high-priority issues based on their complexity or limited lifecycle support. Therefore, lower-priority issues will not receive immediate fixes.
What is a mitigation?
I have a Red Hat product but it is not in the above list, is it affected?
Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?
My product is listed as "Out of Support Scope". What does this mean?
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