🛡️ CVE-2026-23380 on Ubuntu — linux

⚪ Unknown ✅ No Known Exploit OSV
N/A
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

In the Linux kernel, the following vulnerability has been resolved: tracing: Fix WARN_ON in tracing_buffers_mmap_close When a process forks, the child process copies the parent's VMAs but the user_mapped reference count is not incremented. As a result, when both the parent and child processes exit, tracing_buffers_mmap_close() is called twice. On the second call, user_mapped is already 0, causing the function to return -ENODEV and triggering a WARN_ON. Normally, this isn't an issue as the memory is mapped with VM_DONTCOPY set. But this is only a hint, and the application can call madvise(MADVISE_DOFORK) which resets the VM_DONTCOPY flag. When the application does that, it can trigger this issue on fork. Fix it by incrementing the user_mapped reference count without re-mapping the pages in the VMA's open callback.

Distribution advisory

This page covers CVE-2026-23380 as tracked by Ubuntu, for the package linux. No fixed version has been recorded for this distribution yet.

How this vulnerability can be exploited

This issue can be reached with local access to the system, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity none, availability high.

Affected software and timeline

Affected software: linux, linux-allwinner-5.19, linux-aws, linux-aws-5.0, linux-aws-5.11, linux-aws-5.13, linux-aws-5.19, linux-aws-5.3, linux-aws-5.8, linux-aws-6.14, linux-aws-6.17, linux-aws-6.2, linux-aws-6.5, linux-azure, linux-azure-5.11, linux-azure-5.13, linux-azure-5.19, linux-azure-5.3, linux-azure-5.8, linux-azure-6.11, linux-azure-6.14, linux-azure-6.17, linux-azure-6.2, linux-azure-6.5, linux-azure-edge, linux-azure-fde, linux-azure-fde-5.19, linux-azure-fde-6.14, linux-azure-fde-6.17, linux-azure-fde-6.2, linux-azure-nvidia-6.14, linux-bluefield, linux-gcp, linux-gcp-5.11, linux-gcp-5.13, linux-gcp-5.19, linux-gcp-5.3, linux-gcp-5.8, linux-gcp-6.11, linux-gcp-6.14, linux-gcp-6.17, linux-gcp-6.2, linux-gcp-6.5, linux-gke, linux-gke-4.15, linux-gke-5.15, linux-gke-5.4, linux-gkeop, linux-gkeop-5.15, linux-gkeop-5.4, linux-hwe, linux-hwe-5.11, linux-hwe-5.13, linux-hwe-5.19, linux-hwe-5.8, linux-hwe-6.11, linux-hwe-6.14, linux-hwe-6.17, linux-hwe-6.2, linux-hwe-6.5, linux-hwe-edge, linux-intel-5.13, linux-intel-iot-realtime, linux-lowlatency-hwe-5.19, linux-lowlatency-hwe-6.11, linux-lowlatency-hwe-6.2, linux-lowlatency-hwe-6.5, linux-nvidia, linux-nvidia-6.11, linux-nvidia-6.17, linux-nvidia-6.2, linux-nvidia-6.5, linux-oem, linux-oem-5.10, linux-oem-5.13, linux-oem-5.14, linux-oem-5.17, linux-oem-5.6, linux-oem-6.0, linux-oem-6.1, linux-oem-6.11, linux-oem-6.14, linux-oem-6.17, linux-oem-6.5, linux-oem-6.8, linux-oracle, linux-oracle-5.0, linux-oracle-5.11, linux-oracle-5.13, linux-oracle-5.3, linux-oracle-5.8, linux-oracle-6.14, linux-oracle-6.17, linux-oracle-6.5, linux-raspi, linux-raspi-realtime, linux-raspi2, linux-realtime, linux-realtime-6.14, linux-realtime-6.17, linux-riscv, linux-riscv-5.11, linux-riscv-5.19, linux-riscv-5.8, linux-riscv-6.14, linux-riscv-6.17, linux-riscv-6.5, linux-starfive-5.19, linux-starfive-6.2 and linux-starfive-6.5. Published on 25 March 2026 and last revised on 11 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

ubuntu.com (Report)
www.cve.org (Report)
git.kernel.org (Report)
git.kernel.org (Report)
git.kernel.org (Report)
git.kernel.org (Report)
git.kernel.org (Report)

CVE-2026-23380 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity Unknown
CVSS Score N/A
CVSS Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE N/A
Public Exploit ✅ No
Source OSV
Published 2026-03-25
Updated 2026-08-12
Modified 2026-08-11
Fix URL N/A

Affected Packages

Software From version Fixed in
linux
linux-allwinner-5.19
linux-aws
linux-aws-5.0
linux-aws-5.11
linux-aws-5.13
linux-aws-5.19
linux-aws-5.3
linux-aws-5.8
linux-aws-6.14
linux-aws-6.17
linux-aws-6.2
linux-aws-6.5
linux-azure
linux-azure-5.11
linux-azure-5.13
linux-azure-5.19
linux-azure-5.3
linux-azure-5.8
linux-azure-6.11
linux-azure-6.14
linux-azure-6.17
linux-azure-6.2
linux-azure-6.5
linux-azure-edge
linux-azure-fde
linux-azure-fde-5.19
linux-azure-fde-6.14
linux-azure-fde-6.17
linux-azure-fde-6.2
linux-azure-nvidia-6.14
linux-bluefield
linux-gcp
linux-gcp-5.11
linux-gcp-5.13
linux-gcp-5.19
linux-gcp-5.3
linux-gcp-5.8
linux-gcp-6.11
linux-gcp-6.14
linux-gcp-6.17
linux-gcp-6.2
linux-gcp-6.5
linux-gke
linux-gke-4.15
linux-gke-5.15
linux-gke-5.4
linux-gkeop
linux-gkeop-5.15
linux-gkeop-5.4
linux-hwe
linux-hwe-5.11
linux-hwe-5.13
linux-hwe-5.19
linux-hwe-5.8
linux-hwe-6.11
linux-hwe-6.14
linux-hwe-6.17
linux-hwe-6.2
linux-hwe-6.5
linux-hwe-edge
linux-intel-5.13
linux-intel-iot-realtime
linux-lowlatency-hwe-5.19
linux-lowlatency-hwe-6.11
linux-lowlatency-hwe-6.2
linux-lowlatency-hwe-6.5
linux-nvidia
linux-nvidia-6.11
linux-nvidia-6.17
linux-nvidia-6.2
linux-nvidia-6.5
linux-oem
linux-oem-5.10
linux-oem-5.13
linux-oem-5.14
linux-oem-5.17
linux-oem-5.6
linux-oem-6.0
linux-oem-6.1
linux-oem-6.11
linux-oem-6.14
linux-oem-6.17
linux-oem-6.5
linux-oem-6.8
linux-oracle
linux-oracle-5.0
linux-oracle-5.11
linux-oracle-5.13
linux-oracle-5.3
linux-oracle-5.8
linux-oracle-6.14
linux-oracle-6.17
linux-oracle-6.5
linux-raspi
linux-raspi-realtime
linux-raspi2
linux-realtime
linux-realtime-6.14
linux-realtime-6.17
linux-riscv
linux-riscv-5.11
linux-riscv-5.19
linux-riscv-5.8
linux-riscv-6.14
linux-riscv-6.17
linux-riscv-6.5
linux-starfive-5.19
linux-starfive-6.2
linux-starfive-6.5

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