CVE-2026-23248Improper Update of Reference Count in Linux

Severity
7.8HIGHNVD
EPSS
0.0%
top 97.88%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
Timeline
PublishedMar 18

Description

In the Linux kernel, the following vulnerability has been resolved: perf/core: Fix refcount bug and potential UAF in perf_mmap Syzkaller reported a refcount_t: addition on 0; use-after-free warning in perf_mmap. The issue is caused by a race condition between a failing mmap() setup and a concurrent mmap() on a dependent event (e.g., using output redirection). In perf_mmap(), the ring_buffer (rb) is allocated and assigned to event->rb with the mmap_mutex held. The mutex is then released to pe

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 Packages3 packages

Linuxlinux/linux_kernel6.14.06.18.17+1
Debianlinux/linux_kernel< 6.19.8-1
CVEListV5linux/linuxb709eb872e19a19607bbb6d2975bc264d59735cfc27dea9f50ed525facb62ef647dddc4722456e07+3

🔴Vulnerability Details

4
OSV
perf/core: Fix refcount bug and potential UAF in perf_mmap2026-03-18
CVEList
perf/core: Fix refcount bug and potential UAF in perf_mmap2026-03-18
GHSA
GHSA-78fw-h7fp-fffh: In the Linux kernel, the following vulnerability has been resolved: perf/core: Fix refcount bug and potential UAF in perf_mmap Syzkaller reported a2026-03-18
OSV
CVE-2026-23248: In the Linux kernel, the following vulnerability has been resolved: perf/core: Fix refcount bug and potential UAF in perf_mmap Syzkaller reported a re2026-03-18

📋Vendor Advisories

3
Red Hat
kernel: perf/core: Fix refcount bug and potential UAF in perf_mmap2026-03-18
Microsoft
perf/core: Fix refcount bug and potential UAF in perf_mmap2026-03-10
Debian
CVE-2026-23248: linux - In the Linux kernel, the following vulnerability has been resolved: perf/core: ...2026

🕵️Threat Intelligence

1
Wiz
CVE-2026-23248 Impact, Exploitability, and Mitigation Steps | Wiz
CVE-2026-23248 — Improper Update of Reference Count | cvebase