CVE-2025-21762 | arp: use RCU protection in arp_xmit()

In the Linux kernel, the following vulnerability has been resolved: arp: use RCU protection in arp_xmit() arp_xmit() can be called without RTNL or RCU protection. Use RCU protection to avoid 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-2025-21762 is rated Low Risk (36.1/100): CVSS High severity, with low exploitation likelihood (EPSS 0.23%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

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-2025-21762

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 2026-06-15 0.01% 0.23% +0.21%
2 2026-04-30 0.05% 0.01% -0.04%
3 2026-04-07 — 0.05% —

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-21762

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-2025-21762

GitHub Security Advisory for CVE-2025-21762

GHSA-3vhc-4mgh-2vvp · Severity: high — In the Linux kernel, the following vulnerability has been resolved: arp: use RCU protection in...

OS Trackers for CVE-2025-21762

vendor priority summary link
debian not yet assigned CVE-2025-21762 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-2025-21762
redhat medium — https://access.redhat.com/security/cve/CVE-2025-21762
suse medium — https://www.suse.com/security/cve/CVE-2025-21762/
ubuntu medium CVE-2025-21762 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 153, not-affected 44, needed 20. https://ubuntu.com/security/CVE-2025-21762

Affected software / configurations for CVE-2025-21762

Vendor Product Version Raw CPE
linux linux_kernel >= 4.4, < 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-2025-21762

URL Tags
https://git.kernel.org/stable/c/01d1b5c9abcaff29a43f1d17a19c33eec92c7dbe Patch
https://git.kernel.org/stable/c/10f555e3f573d004ae9d89b3276abb58c4ede5c3 Patch
https://git.kernel.org/stable/c/2c331718d3389b6c5f6855078ab7171849e016bd Patch
https://git.kernel.org/stable/c/307cd1e2d3cb1cbc6c40c679cada6d7168b18431 Patch
https://git.kernel.org/stable/c/a42b69f692165ec39db42d595f4f65a4c8f42e44 Patch
https://git.kernel.org/stable/c/d9366ac2f956a1948b68c0500f84a3462ff2ed8a Patch
https://git.kernel.org/stable/c/e9f4dee534eb1b225b0a120395ad9bc2afe164d3 Patch
https://git.kernel.org/stable/c/f189654459423d4d48bef2d120b4bfba559e6039 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
https://cert-portal.siemens.com/productcert/html/ssa-503939.html
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