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High

Use-after-free in Linux kernel Bluetooth SCO sco_recv_frame()

IdentifiersCVE-2026-31408CWE-416· Use After Free

CVE-2026-31408 is a use-after-free vulnerability in the Linux kernel Bluetooth SCO subsystem, specifically in sco_recv_frame(). The function reads conn->sk while holding sco_conn_lock(), but releases the lock without first taking a reference to the socket. If a concurrent close() occurs after the lock is released, the socket can be freed before subsequent access to sk->sk_state, resulting in a dangling pointer dereference and use-after-free condition. The issue is caused by missing reference management for the socket object in a race window between lock release and later socket state access. The upstream fix takes a reference with sco_sock_hold() before releasing the lock and adds sock_put() on all exit paths.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation can lead to kernel memory corruption in the Bluetooth SCO path. Because this is a use-after-free in kernel context, impact can include kernel crash or denial of service, and potentially compromise of confidentiality, integrity, and availability depending on exploitability and target conditions. The provided context includes CVSS v3.1 scoring from NVD/Linux Kernel CNA of 8.8 with vector AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H, indicating adjacent-network reachability and potentially severe impact.

Mitigation

If you can’t patch tonight, do this now.

Until patched kernels can be deployed, reduce exposure by disabling or restricting Bluetooth functionality, especially SCO-related use, on systems where it is not required. Limit adjacent-network Bluetooth attack surface by turning off Bluetooth adapters, blocking device pairing/use, or unloading/disabling Bluetooth kernel modules where operationally feasible. These are compensating controls only; the definitive mitigation is installation of a fixed kernel.

Remediation

Patch, then assume compromise.

Apply a kernel update that includes the upstream fix for CVE-2026-31408. The fix modifies sco_recv_frame() to acquire a socket reference with sco_sock_hold() while still under sco_conn_lock(), and to release that reference with sock_put() on all exit paths. Vendor advisories in the provided content indicate fixes are available in multiple SUSE kernel package lines; administrators should install the relevant patched kernel packages for their distribution and reboot into the updated kernel.
PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType
LinuxLinux Kerneloperating_system

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

9 sources tracked across advisories and community write-ups. News coverage will land here when it surfaces.

No news coverage yet. Advisories and community discussion only.

What this page doesn’t show

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Exposure mapping

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Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity2

Community discussion across Reddit, Mastodon, and other social sources.