CVE-2025-21760 | ndisc: extend RCU protection in ndisc_send_skb()

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.

Published: 2025-02-27 Last update: 2026-05-12 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-21760 is rated Moderate Risk (44.8/100): CVSS High severity, with low exploitation likelihood (EPSS 0.17%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-21760

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-09 0.06% 0.17% +0.11%
2 2026-04-07 0.04% 0.06% +0.02%
3 2025-11-21 — 0.04% —

Full EPSS history (5 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-21760

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2025-21760

GitHub Security Advisory for CVE-2025-21760

GHSA-wm97-xp23-f4x4 · Severity: high — In the Linux kernel, the following vulnerability has been resolved: ndisc: extend RCU protection...

OS Trackers for CVE-2025-21760

vendor priority summary link
debian not yet assigned CVE-2025-21760 not yet assigned priority: Debian including 2 source packages (linux, linux-6.1), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 6. https://security-tracker.debian.org/tracker/CVE-2025-21760
redhat medium — https://access.redhat.com/security/cve/CVE-2025-21760
suse medium — https://www.suse.com/security/cve/CVE-2025-21760/
ubuntu medium CVE-2025-21760 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1551 status rows across 10 suites (bionic, focal, jammy, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 1145, released 189, ignored 154, not-affected 43, needed 20. https://ubuntu.com/security/CVE-2025-21760

Affected software / configurations for CVE-2025-21760

Vendor Product Version Raw CPE
linux linux_kernel >= 2.6.26, < 5.4.291 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.5, < 5.10.235 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.11, < 5.15.179 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.16, < 6.1.129 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.2, < 6.6.79 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.7, < 6.12.16 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.13, < 6.13.4 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel 6.14 cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:*
linux linux_kernel 6.14 cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:*

References for CVE-2025-21760

URL Tags
https://git.kernel.org/stable/c/04e05112f10354ffc3bb6cc796d553bab161594c Patch
https://git.kernel.org/stable/c/10a1f3fece2f0d23a3a618b72b2b4e6f408ef7d1 Patch
https://git.kernel.org/stable/c/4d576202b90b1b95a7c428a80b536f91b8201bcc Patch
https://git.kernel.org/stable/c/789230e5a8c1097301afc802e242c79bc8835c67 Patch
https://git.kernel.org/stable/c/a9319d800b5701e7f5e3fa71a5b7c4831fc20d6d Patch
https://git.kernel.org/stable/c/ae38982f521621c216fc2f5182cd091f4734641d Patch
https://git.kernel.org/stable/c/e24d225e4cb8cf108bde00b76594499b98f0a74d Patch
https://git.kernel.org/stable/c/ed6ae1f325d3c43966ec1b62ac1459e2b8e45640 Patch
https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html
https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html
https://cert-portal.siemens.com/productcert/html/ssa-265688.html
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