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Fencer Vulns
high 7.8

CVE-2025-21761 json

openvswitch: use RCU protection in ovs_vport_cmd_fill_info()

published 2025-02-27 20 mo ago modified 2026-10-15 25 d ago also EUVD-2025-5156

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 17%
public exploits
0
none known

Summary

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

openvswitch: use RCU protection in ovs_vport_cmd_fill_info()

ovs_vport_cmd_fill_info() can be called without RTNL or RCU.

Use RCU protection and dev_net_rcu() to avoid potential UAF.

Patch / fix

  • Linux Linux 5.4.291, 5.10.235, 5.15.179, 6.1.129, 6.6.79, 6.12.16, 6.13.4, 6.14
  • linux Debian 12 6.1.129-1
  • linux Debian 14, Debian 13 6.12.16-1

debian advisories DEBIAN-CVE-2025-21761

  • 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 6.8.0-78.78
  • 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 6.8.0-1035.37
  • 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-2025-21761

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 10.1 6.12.0-124.8.1.el10_1
  • rv RHEL 10.1 6.12.0-124.8.1.el10_1
  • perf RHEL 10.1 6.12.0-124.8.1.el10_1
  • rtla RHEL 10.1 6.12.0-124.8.1.el10_1
  • libperf RHEL 10.1 6.12.0-124.8.1.el10_1
  • kernel-rt RHEL 10.1 6.12.0-124.8.1.el10_1
  • kernel-64k RHEL 10.1 6.12.0-124.8.1.el10_1
  • kernel-core RHEL 10.1 6.12.0-124.8.1.el10_1

red hat advisories RHSA-2025:20095

  • kernel-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.20.3.1
  • kernel-syms-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.20.3.1
  • kernel-source-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.20.3.1
  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.3.1
  • kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.3.1
  • kernel-source SLE Module for Development Tools 15 SP7, SLE Module for Basesystem 15 SP7 6.4.0-150700.53.3.1
  • kernel-default SLE Workstation Extension 15 SP7, SLE Module for Legacy 15 SP7, SLE Module for Basesystem 15 SP7 +2 more 6.4.0-150700.53.3.1
  • kernel-zfcpdump SLE Module for Basesystem 15 SP7 6.4.0-150700.53.3.1

suse advisories SUSE-SU-2025:01967-1SUSE-SU-2025:01951-1SUSE-SU-2025:01919-1SUSE-SU-2025:20192-1SUSE-SU-2025:20270-1SUSE-SU-2025:20190-1

  • kernel AlmaLinux 10 6.12.0-124.8.1.el10_1
  • rv AlmaLinux 10 6.12.0-124.8.1.el10_1
  • perf AlmaLinux 10 6.12.0-124.8.1.el10_1
  • rtla AlmaLinux 10 6.12.0-124.8.1.el10_1
  • libperf AlmaLinux 10 6.12.0-124.8.1.el10_1
  • kernel-rt AlmaLinux 10 6.12.0-124.8.1.el10_1
  • kernel-64k AlmaLinux 10 6.12.0-124.8.1.el10_1
  • kernel-core AlmaLinux 10 6.12.0-124.8.1.el10_1

almalinux advisories ALSA-2025:20095

  • kernel Rocky Linux 10 6.12.0-124.8.1.el10_1

rocky linux advisories RLSA-2025:20095

  • kernel CBL-Mariner 2.0 5.15.180.1-1
  • kernel Azure Linux 3.0 6.6.82.1-1

azure linux advisories AZL-59058AZL-59082

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

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-2025-21761 updated cvss 7.0

kernel: openvswitch: use RCU protection in ovs_vport_cmd_fill_info()

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more 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: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +82 more
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-124.8.1.el10_1, perf 6.12.0-124.8.1.el10_1, rtla 6.12.0-124.8.1.el10_1, python3-perf 6.12.0-124.8.1.el10_1, kernel-devel-matched 6.12.0-124.8.1.el10_1, kernel-64k-devel-matched 6.12.0-124.8.1.el10_1, +7 more Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-124.8.1.el10_1, kernel-64k 6.12.0-124.8.1.el10_1, kernel-core 6.12.0-124.8.1.el10_1, kernel-tools 6.12.0-124.8.1.el10_1, kernel-modules 6.12.0-124.8.1.el10_1, kernel-64k-core 6.12.0-124.8.1.el10_1, +28 more Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-124.8.1.el10_1, kernel-debuginfo-common-s390x 6.12.0-124.8.1.el10_1, kernel-debuginfo-common-x86_64 6.12.0-124.8.1.el10_1, kernel-debuginfo-common-aarch64 6.12.0-124.8.1.el10_1, kernel-debuginfo-common-ppc64le 6.12.0-124.8.1.el10_1 Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-124.8.1.el10_1, kernel-rt-64k 6.12.0-124.8.1.el10_1, kernel-rt-core 6.12.0-124.8.1.el10_1, kernel-rt-modules 6.12.0-124.8.1.el10_1, kernel-rt-64k-core 6.12.0-124.8.1.el10_1, kernel-rt-debug-core 6.12.0-124.8.1.el10_1, +14 more Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-124.8.1.el10_1, kernel-rt-core 6.12.0-124.8.1.el10_1, kernel-rt-modules 6.12.0-124.8.1.el10_1, kernel-rt-debug-core 6.12.0-124.8.1.el10_1, kernel-rt-modules-core 6.12.0-124.8.1.el10_1, kernel-rt-debug-modules 6.12.0-124.8.1.el10_1, +4 more
    fixed: vendor fix RHSA-2025:20095

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 cvss 7.8

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 cvss 7.8

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 SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
20 mo ago

Exploit prediction

0.26% chance of exploitation in the next 30 days, higher than 17% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CISA ADP 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux
  • Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem

Classification

Weakness
Technology feeds

References

Sources

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.