CVE-2025-39702 ipv6: sr: Fix MAC comparison to be constant-time
An attacker can exploit timing side-channels in IPv6 Segment Routing MAC comparisons to potentially recover sensitive cryptographic material.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-39702?
CVE-2025-39702 is a critical vulnerability in Debian Debian Linux, published on 5 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-203
Which versions are affected by CVE-2025-39702?
It affects 2 products.
Products include Debian Debian Linux, Linux kernel.
How do I fix CVE-2025-39702?
Apply the vendor's patch.
Is CVE-2025-39702 being exploited?
There is no known exploitation of CVE-2025-39702 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as AZL-66941, AZL-73719, BELL-CVE-2025-39702, DEBIAN-CVE-2025-39702, GHSA-37gv-w6h3-7hm7, ROOT-OS-DEBIAN-11-CVE-2025-39702 and 5 more.