Quick answers
- Is CVE-2026-64542 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-64542 being exploited in the wild.
- How severe is CVE-2026-64542?
- Informational severity, with a CVSS score of 6.2, published 27 July 2026.
- Which products and versions are affected?
- Linux Kernel 6.0 to 6.12.97, 6.18.40, 7.1.5.
- Is there a fix for CVE-2026-64542?
- A patch was published on 2026-07-24: Commits merged into stable branches Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-64542 attacked?
- It is attacked over the network, in an operating system.
- Am I affected by CVE-2026-64542?
- Check whether you run Linux Kernel at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A race condition exists in the IPv6 Neighbor Discovery (ndisc) component of the Linux kernel. Specifically, the function accept_untracked_na() re-fetches the inet6_dev pointer without a NULL check. If a concurrent event, such as lowering the MTU below the minimum required for IPv6, triggers addrconf_ifdown(), the pointer can be cleared between the initial check and the subsequent dereference. This results in a NULL pointer dereference and a kernel oops. The vulnerability is reachable by unprivileged users via network namespaces. The fix involves passing the already validated idev pointer from the caller to ensure it remains valid throughout the RCU critical section.
Affected products
- Linux Linux Kernel 6.0 to 6.12.97, 6.18.40, 7.1.5
Timeline
- 2026-06-17: disclosed: Initial patch submitted by Weiming Shi
- 2026-07-24: patched: Commits merged into stable branches
- 2026-07-27: advisory: CVE-2026-64542 published