medium 5.5

CVE-2025-21728 json

bpf: Send signals asynchronously if !preemptible

published 2025-02-27 20 mo ago modified 2026-10-15 25 d ago also EUVD-2025-5223

cvss: 5.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 11%
public exploits: 0; none known

In the Linux kernel, the following vulnerability has been resolved:

BPF programs can execute in all kinds of contexts and when a program running in a non-preemptible context uses the bpf_send_signal() kfunc, it will cause issues because this kfunc can sleep. Change `irqs_disabled()` to `!preemptible()`.

Patch / fix

fixed in 1 distros 6 links 8

Linux Linux 5.4.291, 5.6, 5.10.235, 5.15.179, 6.1.129, 6.6.76, 6.12.13, 6.13.2, 6.14

debian ubuntu red hat suse almalinux rocky linux

linux Debian 12 6.1.129-1
linux Debian 14, Debian 13 6.12.13-1

debian advisories DEBIAN-CVE-2025-21728

linux Ubuntu 20.04 LTS 5.4.0-216.236
linux Ubuntu 22.04 LTS 5.15.0-140.150
linux Ubuntu 24.04 LTS 6.8.0-64.67
linux-aws Ubuntu 20.04 LTS 5.4.0-1146.156
linux-aws Ubuntu 22.04 LTS 5.15.0-1084.91
linux-aws Ubuntu 24.04 LTS 6.8.0-1032.34
linux-gcp Ubuntu 20.04 LTS 5.4.0-1149.158
linux-gcp Ubuntu 22.04 LTS 5.15.0-1083.92

ubuntu advisories UBUNTU-CVE-2025-21728

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

kernel RHEL 9 5.14.0-611.5.1.el9_7
rv RHEL 9 5.14.0-611.5.1.el9_7
perf RHEL 9 5.14.0-611.5.1.el9_7
rtla RHEL 9 5.14.0-611.5.1.el9_7
libperf RHEL 9 5.14.0-611.5.1.el9_7
kernel-rt RHEL 9 5.14.0-611.5.1.el9_7
kernel-64k RHEL 9 5.14.0-611.5.1.el9_7
kernel-core RHEL 9 5.14.0-611.5.1.el9_7

red hat advisories RHSA-2025:20518

kernel-coco SLE Module for Confidential Computing Technical Preview 15 SP6 6.4.0-15061.21.coco15sp6.1
kernel-syms-coco SLE Module for Confidential Computing Technical Preview 15 SP6 6.4.0-15061.21.coco15sp6.1
kernel-coco_debug SLE Module for Confidential Computing Technical Preview 15 SP6 6.4.0-15061.21.coco15sp6.1
kernel-source-coco SLE Module for Confidential Computing Technical Preview 15 SP6 6.4.0-15061.21.coco15sp6.1
kernel-source Linux Micro 6.1, Linux Micro 6.0 6.4.0-28.1
kernel-default Linux Micro 6.1, Linux Micro 6.0 6.4.0-28.1
kernel-kvmsmall Linux Micro 6.1, Linux Micro 6.0 6.4.0-28.1
kernel-default-base Linux Micro 6.1, Linux Micro 6.0 6.4.0-28.1.21.6

suse advisories SUSE-SU-2025:01919-1 SUSE-SU-2025:20192-1 SUSE-SU-2025:20270-1 SUSE-SU-2025:20190-1 SUSE-SU-2025:20260-1 SUSE-SU-2025:0955-1

kernel AlmaLinux 9 5.14.0-611.5.1.el9_7
rv AlmaLinux 9 5.14.0-611.5.1.el9_7
perf AlmaLinux 9 5.14.0-611.5.1.el9_7
rtla AlmaLinux 9 5.14.0-611.5.1.el9_7
libperf AlmaLinux 9 5.14.0-611.5.1.el9_7
kernel-rt AlmaLinux 9 5.14.0-611.5.1.el9_7
kernel-64k AlmaLinux 9 5.14.0-611.5.1.el9_7
kernel-core AlmaLinux 9 5.14.0-611.5.1.el9_7

almalinux advisories ALSA-2025:20518

kernel Rocky Linux 9 5.14.0-611.5.1.el9_7

rocky linux advisories RLSA-2025:20518

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-21728 updated 2026-11-05 cvss 4.4

kernel: bpf: Send signals asynchronously if !preemptible

Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more
affected: no fix planned “Out of support scope”
Red Hat Enterprise Linux 10 kernel
affected: no fix available “Fix deferred”
Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-611.5.1.el9_7, perf 5.14.0-611.5.1.el9_7, rtla 5.14.0-611.5.1.el9_7, python3-perf 5.14.0-611.5.1.el9_7, kernel-devel-matched 5.14.0-611.5.1.el9_7, kernel-64k-devel-matched 5.14.0-611.5.1.el9_7, +7 more Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-611.5.1.el9_7, kernel-64k 5.14.0-611.5.1.el9_7, kernel-core 5.14.0-611.5.1.el9_7, kernel-tools 5.14.0-611.5.1.el9_7, kernel-modules 5.14.0-611.5.1.el9_7, kernel-64k-core 5.14.0-611.5.1.el9_7, +27 more Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-611.5.1.el9_7, kernel-debuginfo-common-s390x 5.14.0-611.5.1.el9_7, kernel-debuginfo-common-x86_64 5.14.0-611.5.1.el9_7, kernel-debuginfo-common-aarch64 5.14.0-611.5.1.el9_7, kernel-debuginfo-common-ppc64le 5.14.0-611.5.1.el9_7 Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-611.5.1.el9_7, kernel-rt-64k 5.14.0-611.5.1.el9_7, kernel-rt-core 5.14.0-611.5.1.el9_7, kernel-rt-modules 5.14.0-611.5.1.el9_7, kernel-rt-64k-core 5.14.0-611.5.1.el9_7, kernel-rt-debug-core 5.14.0-611.5.1.el9_7, +14 more Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-611.5.1.el9_7, kernel-rt-core 5.14.0-611.5.1.el9_7, kernel-rt-modules 5.14.0-611.5.1.el9_7, kernel-rt-debug-core 5.14.0-611.5.1.el9_7, kernel-rt-modules-core 5.14.0-611.5.1.el9_7, kernel-rt-debug-modules 5.14.0-611.5.1.el9_7, +4 more
fixed: vendor fix RHSA-2025:20518
Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

cisa ICSA-26-295-16 updated 2026-10-22 cvss 5.5

Siemens SIMATIC S7-1500 TM MFP

Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
affected: mitigation, no fix available

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

cisa ICSA-24-102-01 updated 2026-05-14 cvss 5.5

Siemens SIMATIC S7-1500 TM MFP

Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
affected: mitigation, no fix available

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

cisa ICSA-25-162-05 updated 2026-05-14 cvss 5.5

Siemens SIMATIC S7-1500 CPU family

Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= 3.1.5 Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= 3.1.5 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= 3.1.5 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) >= 3.1.5 Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) >= 3.1.5
affected: mitigation, no fix available

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

Exploit prediction

0.21% chance of exploitation in the next 30 days, higher than 11% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.1	5.5	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

Linux Linux
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP
Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP

Classification

Technology feeds

Linux kernel rss critical rss

References

Sources

CVE List CVE-2025-21728
NVD CVE-2025-21728

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary

Patch / fix

Vendor advisories

Exploit prediction

CVSS scores

Affected products

Classification

References

Sources