In the Linux kernel, the following vulnerability has been resolved: tunnels: do not assume transport header in iptunnel_pmtud_check_icmp() In some cases, iptunnel_pmtud_check_icmp() can be called while skb transport header is not set. This triggers an out-of-bound access, because (typeof(skb->transport_header))~0U is 65535. Access the icmp header based on IPv4 network header, after making sure icmp->type is present in skb linear part. Note that iptunnel_pmtud_check_icmpv6()) is fine.

An update of the linux package has been released.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - tunnels: do not assume transport header in iptunnel_pmtud_check_icmp() In some cases,     iptunnel_pmtud_check_icmp() can be called while skb transport header is not set. This triggers an out-of-     bound access, because (typeof(skb->transport_header))~0U is 65535. Access the icmp header based on IPv4     network header, after making sure icmp->type is present in skb linear part. Note that     iptunnel_pmtud_check_icmpv6()) is fine. (CVE-2026-63992)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
333941	Photon OS 5.0: Linux PHSA-2026-5.0-92-0926	Nessus	PhotonOS Local Security Checks	Local	high
333762	Photon OS 5.0: Linux PHSA-2026-5.0-92-0895	Nessus	PhotonOS Local Security Checks	Local	high
329326	Photon OS 5.0: Linux PHSA-2026-5.0-0926	Nessus	PhotonOS Local Security Checks	Local	high
328499	Amazon Linux 2 : kernel, --advisory ALAS2KERNEL-5.15-2026-110 (ALASKERNEL-5.15-2026-110)	Nessus	Amazon Linux Local Security Checks	Local	medium
328493	Amazon Linux 2023 : bpftool6.12, kernel6.12, kernel6.12-devel (ALAS2023-2026-1968)	Nessus	Amazon Linux Local Security Checks	Local	high
328291	Linux Distros Unpatched Vulnerability : CVE-2026-63992	Nessus	Misc.	Local	critical
327380	Amazon Linux 2023 : bpftool, kernel, kernel-devel (ALAS2023-2026-1924)	Nessus	Amazon Linux Local Security Checks	Local	medium
325574	Amazon Linux 2 : kernel, --advisory ALAS2KERNEL-5.10-2026-124 (ALASKERNEL-5.10-2026-124)	Nessus	Amazon Linux Local Security Checks	Local	high
322944	Photon OS 5.0: Linux PHSA-2026-5.0-0895	Nessus	PhotonOS Local Security Checks	Local	high
322087	Amazon Linux 2023 : bpftool6.18, kernel6.18, kernel6.18-devel (ALAS2023-2026-1881)	Nessus	Amazon Linux Local Security Checks	Local	medium

Detections

Analytics

CVE-2026-63992

critical

Tenable Plugins

high

high

high

medium

high

critical

medium

high

high

medium