CVE-2025-39702

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.

This vulnerability is rated as having Moderate impact because exploiting timing side channels to deduce authentication tags requires high-precision observation and extensive sampling rather than providing direct system compromise. Furthermore, the issue only affects systems configured to use IPv6 Segment Routing HMAC verification, which is an advanced networking feature not enabled by default in standard Red Hat Enterprise Linux environments. Consequently, typical configurations that do not utilize SRv6 authentication are not exposed to this flaw.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.