CVE-2025-21760 in the critical feed json
ndisc: extend RCU protection in ndisc_send_skb()
published 2025-02-27 20 mo ago modified 2026-10-15 25 d ago also EUVD-2025-5152
- cvss
- 8.1
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 38.0%
- EPSS 38.0% chance of exploitation in 30 days, percentile 98%
- public exploits
- 0
- none known
Summary
In the Linux kernel, the following vulnerability has been resolved:
ndisc: extend RCU protection in ndisc_send_skb()
ndisc_send_skb() can be called without RTNL or RCU held.
Acquire rcu_read_lock() earlier, so that we can use dev_net_rcu() and avoid a 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-2025-21760
- 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-2025-21760
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-rt SLE Micro 5.4, SLE Micro 5.3 5.14.21-150400.15.145.1
- kernel-source-rt SLE Micro 5.4, SLE Micro 5.3 5.14.21-150400.15.145.1
- kernel-64kb SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS, SLE High Performance Computing 15 SP4-ESPOS 5.14.21-150400.24.194.1
- kernel-syms SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +1 more 5.14.21-150400.24.194.1
- kernel-source SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +1 more 5.14.21-150400.24.194.1
- kernel-default SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +5 more 5.14.21-150400.24.194.1
- kernel-obs-build SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +1 more 5.14.21-150400.24.194.1
- kernel-default-base SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +3 more 5.14.21-150400.24.194.1.150400.24.98.3
suse advisories SUSE-SU-2026:1131-1SUSE-SU-2026:0617-1SUSE-SU-2026:0496-1SUSE-SU-2026:0495-1SUSE-SU-2026:0475-1SUSE-SU-2026:0474-1
- kernel CBL-Mariner 2.0 5.15.180.1-1
- kernel Azure Linux 3.0 6.6.82.1-1
azure linux advisories AZL-58962AZL-59085
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
- git.kernel.org/stable/c/10a1f3fece2f0d23a3a618b72b2b4e6f408ef7d1 commit
- git.kernel.org/stable/c/4d576202b90b1b95a7c428a80b536f91b8201bcc commit
- git.kernel.org/stable/c/e24d225e4cb8cf108bde00b76594499b98f0a74d commit
- git.kernel.org/stable/c/a9319d800b5701e7f5e3fa71a5b7c4831fc20d6d commit
- git.kernel.org/stable/c/ae38982f521621c216fc2f5182cd091f4734641d commit
- git.kernel.org/stable/c/789230e5a8c1097301afc802e242c79bc8835c67 commit
- git.kernel.org/stable/c/04e05112f10354ffc3bb6cc796d553bab161594c commit
- git.kernel.org/stable/c/ed6ae1f325d3c43966ec1b62ac1459e2b8e45640 commit
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-2025-21760 updated cvss 5.5
kernel: ndisc: extend RCU protection in ndisc_send_skb()
-
Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 moreaffected: no fix planned “Out of support scope”
-
Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 moreaffected: no fix available “Fix deferred”
-
Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 moreaffected: no fix available
-
Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +82 more Red Hat Enterprise Linux 10 kernelaffected: no fix planned “Will not fix”
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-26-295-11 updated cvss 8.1
Siemens SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP
-
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= 3.1.7 Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= 3.1.7 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= 3.1.7 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) >= 3.1.7 Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) >= 3.1.7affected: 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-26-295-16 updated cvss 8.1
Siemens SIMATIC S7-1500 TM MFP
-
Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystemaffected: 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-26-209-04 updated cvss 7.8
Siemens SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP
-
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= 3.1.6 Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= 3.1.6 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= 3.1.6 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) >= 3.1.6 Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) >= 3.1.6affected: 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 subsystemaffected: 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
38.00% chance of exploitation in the next 30 days, higher than 98% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 8.1 | CVSS:3.1/AV:N/AC:H/PR:N/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 |
| CNA | 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 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
- Weakness
-
- CWE-416 Use After Free
- Technology feeds
References
-
git.kernel.org
/stable/c/10a1f3fece2f0d23a3a618b72b2b4e6f408ef7d1
patch
-
git.kernel.org
/stable/c/4d576202b90b1b95a7c428a80b536f91b8201bcc
patch
-
git.kernel.org
/stable/c/e24d225e4cb8cf108bde00b76594499b98f0a74d
patch
-
git.kernel.org
/stable/c/a9319d800b5701e7f5e3fa71a5b7c4831fc20d6d
patch
-
git.kernel.org
/stable/c/ae38982f521621c216fc2f5182cd091f4734641d
patch
-
git.kernel.org
/stable/c/789230e5a8c1097301afc802e242c79bc8835c67
patch
-
git.kernel.org
/stable/c/04e05112f10354ffc3bb6cc796d553bab161594c
patch
-
git.kernel.org
/stable/c/ed6ae1f325d3c43966ec1b62ac1459e2b8e45640
patch
- lists.debian.org /debian-lts-announce/2025/05/msg00030.html
- lists.debian.org /debian-lts-announce/2025/03/msg00028.html
- cert-portal.siemens.com /productcert/html/ssa-265688.html
- cert-portal.siemens.com /productcert/html/ssa-019113.html
- cert-portal.siemens.com /productcert/html/ssa-457936.html
- cert-portal.siemens.com /productcert/html/ssa-784472.html
Sources
- CVE List CVE-2025-21760
- NVD CVE-2025-21760
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.