Vulnerability in Linux kernel (CVE-2026-46275)
Summary
Vulnerability in Linux kernel (CVE-2026-46275). Successful exploitation can lead to full system takeover.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_uart: fix UAFs and race conditions in close and init paths
Vulnerabilities leading to Use-After-Free (UAF) and Null Pointer
Dereference (NPD) conditions were observed in the lifecycle management
of hci_uart.
The primary issue arises because the workqueues (init_ready and
write_work) are only flushed/cancelled if the HCI_UART_PROTO_READY
flag is set during TTY close. If a hangup occurs before setup completes,
hci_uart_tty_close() skips the teardown of these workqueues and
proceeds to free the hu struct. When the scheduled work executes
later, it blindly dereferences the freed hu struct.
Furthermore, several data races and UAFs were identified in the teardown
sequence:
- Calling hci_uart_flush() from hci_uart_close() without effectively
disabling write_work causes a race condition where both can concurrently
double-free hu->tx_skb. This happens because protocol timers can
concurrently invoke hci_uart_tx_wakeup() and requeue write_work. - Calling hci_free_dev(hdev) before hu->proto->close(hu) causes a UAF
when vendor specific protocol close callbacks dereference hu->hdev. - In the initialization error paths, failing to take the proto_lock
write lock before clearing PROTO_READY leads to races with active
readers. Additionally, hci_uart_tty_receive() accesses hu->hdev
outside the read lock, leading to UAFs if the initialization error
path frees hdev concurrently.…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-46275 has been found in Linux kernel.
Successful exploitation can lead to full system takeover. CVSS score: 7.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2026-46275" on the vendor's site.
CVE-2026-46275 (Linux kernel) — CWE-362 / CVSS v3 7.8
Attack vector: local / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-362) exists in Linux kernel.
Check the vendor advisory for the affected versions of Linux kernel.
Severity: High (CVSS 7.8/10). Successful exploitation can lead to full system takeover.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Linux kernel を使っているサービスとバージョンを洗い出す。
-
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- BellSoft Alpaquita BELL-CVE-2026-46275 linux-lts Fixed in: 6.1.175-r0
- Debian DEBIAN-CVE-2026-46275 linux
- Ubuntu UBUNTU-CVE-2026-46275 linux
References
- advisory nvd.nist.gov
- advisory github.com
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web github.com
- web cert-portal.siemens.com