Critical 9.8Published Sep 5, 2025

CVE-2025-39702ipv6: sr: Fix MAC comparison to be constant-time

Updated under an hour ago (Oct 26, 2026, 6:50 PM ET)

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Exploited in the last 30 days

In the Linux kernel, the following vulnerability has been resolved: ipv6: sr: Fix MAC comparison to be constant-time To prevent timing attacks, MACs need to be compared in constant time. Use the appropriate helper function for this.

CVSS: 9.8 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Modified
Record last updated: Oct 15, 2026
First seen by InfoSec Signals: Oct 15, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from bf355b8d2c30a289232042cacc1cfaea4923936c before ff55a452d56490047f5233cc48c5d933f8586884; from bf355b8d2c30a289232042cacc1cfaea4923936c before 3b348c9c8d2ca2c67559ffd0e258ae7e1107d4f0; from bf355b8d2c30a289232042cacc1cfaea4923936c before 86b6d34717fe0570afce07ee79b8eeb40341f831; from bf355b8d2c30a289232042cacc1cfaea4923936c before 3ddd55cf19ed6cc62def5e3af10c2a9df1b861c3; from bf355b8d2c30a289232042cacc1cfaea4923936c before b3967c493799e63f648e9c7b6cb063aa2aed04e7; from bf355b8d2c30a289232042cacc1cfaea4923936c before f7878d47560d61e3f370aca3cebb8f42a55b990a; from bf355b8d2c30a289232042cacc1cfaea4923936c before a458b2902115b26a25d67393b12ddd57d1216aaa	CNA record
Siemens SIMATIC CN 4100 siemens:simatic_cn_4100 (from the name)	before V5.0	CISA ADP
linux linux_kernel linux:linux_kernel	from 4.10 before 5.15.190; from 5.16 before 6.1.149; from 6.2 before 6.6.103; from 6.7 before 6.12.44; from 6.13 before 6.16.4; 6.17; 6.17	NVD
debian debian_linux debian:debian_linux	11.0	NVD

References

References

https://git.kernel.org/stable/c/ff55a452d56490047f5233cc48c5d933f8586884	patch
https://git.kernel.org/stable/c/3b348c9c8d2ca2c67559ffd0e258ae7e1107d4f0	patch
https://git.kernel.org/stable/c/86b6d34717fe0570afce07ee79b8eeb40341f831	patch
https://git.kernel.org/stable/c/3ddd55cf19ed6cc62def5e3af10c2a9df1b861c3	patch
https://git.kernel.org/stable/c/b3967c493799e63f648e9c7b6cb063aa2aed04e7	patch
https://git.kernel.org/stable/c/f7878d47560d61e3f370aca3cebb8f42a55b990a	patch
https://git.kernel.org/stable/c/a458b2902115b26a25d67393b12ddd57d1216aaa	patch
https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html	mailing-list, third-party-advisory
https://cert-portal.siemens.com/productcert/html/ssa-032379.html

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.