CVE-2026-43099: ipv4: icmp: fix null-ptr-deref in icmp_build_probe()
In the Linux kernel, the following vulnerability has been resolved:
ipv4: icmp: fix null-ptr-deref in icmpbuildprobe()
ipv6stub->ipv6devfind() may return ERRPTR(-EAFNOSUPPORT) when the IPv6 stack is not active (CONFIGIPV6=m and not loaded), and passing this error pointer to devhold() will cause a kernel crash with null-ptr-deref.
Instead, silently discard the request. RFC 8335 does not appear to define a specific response for the case where an IPv6 interface identifier is syntactically valid but the implementation cannot perform the lookup at runtime, and silently dropping the request may safer than misreporting "No Such Interface".
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-43099?
CVE-2026-43099 is classified as a medium-severity vulnerability due to the potential for null-pointer dereference in the icmp_build_probe() function.
How do I fix CVE-2026-43099?
To fix CVE-2026-43099, update the Linux kernel to the latest version where this vulnerability has been patched.
What impact does CVE-2026-43099 have on system security?
CVE-2026-43099 can cause a denial of service condition due to the null-pointer dereference if exploited.
Which systems are affected by CVE-2026-43099?
CVE-2026-43099 affects systems running specific versions of the Linux kernel with IPv6 enabled.
Is CVE-2026-43099 actively being exploited in the wild?
As of now, there are no reported instances of CVE-2026-43099 being actively exploited in the wild.