CVE-2025-21887 — Use After Free in Linux

CWE-416 — Use After Free54 documents7 sources
Severity
7.8HIGHNVD
OSV8.8OSV5.5
EPSS
0.0%
top 91.28%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
8
LinuxLinux KernelDebian Linux+5 more
Timeline
PublishedMar 27
Latest updateOct 8

Description

In the Linux kernel, the following vulnerability has been resolved: ovl: fix UAF in ovl_dentry_update_reval by moving dput() in ovl_link_up The issue was caused by dput(upper) being called before ovl_dentry_update_reval(), while upper->d_flags was still accessed in ovl_dentry_remote(). Move dput(upper) after its last use to prevent use-after-free. BUG: KASAN: slab-use-after-free in ovl_dentry_remote fs/overlayfs/util.c:162 [inline] BUG: KASAN: slab-use-after-free in ovl_dentry_update_reval+0…

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitability: 1.8 | Impact: 5.9

Affected Packages10 packages

▶NVDlinux/linux_kernel5.10.188 — 5.11+7
▶Debianlinux/linux_kernel< 5.10.247-1+3
▶Ubuntulinux/linux_kernel< 5.15.0-140.150+1

Patches

Patch: git.kernel.org ↗Patch: git.kernel.org ↗Patch: git.kernel.org ↗

🔴Vulnerability Details

25
OSV
linux-azure-nvidia vulnerabilities↗2025-10-08
▶
OSV
linux-azure, linux-azure-6.8 vulnerabilities↗2025-10-02
▶
OSV
linux-ibm, linux-ibm-6.8 vulnerabilities↗2025-09-25
▶
OSV
linux-gcp-6.8, linux-gke, linux-gkeop, linux-hwe-6.8, linux-nvidia, linux-nvidia-6.8, linux-nvidia-lowlatency, linux-raspi vulnerabilities↗2025-09-02
▶
OSV
linux-realtime, linux-raspi-realtime vulnerabilities↗2025-08-28
▶

📋Vendor Advisories

28
Ubuntu
Kernel Live Patch Security Notice↗2025-10-08
▶
Ubuntu
Linux kernel (Azure, N-Series) vulnerabilities↗2025-10-08
▶
Ubuntu
Linux kernel (Azure) vulnerabilities↗2025-10-02
▶
Ubuntu
Linux kernel (IBM) vulnerabilities↗2025-09-25
▶
Ubuntu
Linux kernel vulnerabilities↗2025-09-02
▶
CVE-2025-21887 — Use After Free in Linux | cvebase