What’s Vulnerable › Vulnerabilities

CVE-2025-39951: um: virtio_uml: Fix use-after-free after put_device in probe

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-10-04 · updated 2026-10-19
• Weakness: CWE-416

Description

In the Linux kernel, the following vulnerability has been resolved: um: virtio_uml: Fix use-after-free after put_device in probe When register_virtio_device() fails in virtio_uml_probe(), the code sets vu_dev->registered = 1 even though the device was not successfully registered. This can lead to use-after-free or other issues.

Affected products

• Linux kernel: from 5.5 before 5.10.245; from 5.11 before 5.15.194; from 5.16 before 6.1.154; from 6.2 before 6.6.108; from 6.7 before 6.12.49; from 6.13 before 6.16.9 — fixed in 5.10.245, 5.15.194, 6.1.154, 6.12.49, 6.16.9, 6.6.108

How to fix

Upgrade to a fixed version: Linux kernel 5.10.245, 5.15.194, 6.1.154, 6.12.49. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/00e98b5a69034b251bb36dc6e7123d7648e218e4
• https://git.kernel.org/stable/c/14c231959a16ca41bfdcaede72483362a8c645d7
• https://git.kernel.org/stable/c/4f364023ddcfe83f7073b973a9cb98584b7f2a46
• https://git.kernel.org/stable/c/5e94e44c9cb30d7a383d8ac227f24a8c9326b770
• https://git.kernel.org/stable/c/7ebf70cf181651fe3f2e44e95e7e5073d594c9c0
• https://git.kernel.org/stable/c/aaf900a83508c8cd5cdf765e7749f9076196ec7f
• https://git.kernel.org/stable/c/c2ff91255e0157b356cff115d8dc3eeb5162edf2

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