SB2026100668 - Out-of-bounds write in Linux kernel xfrm

Description

This security bulletin contains information about 1 vulnerability.

1) Out-of-bounds write (CVE-ID: CVE-2026-98371)

CWE-ID: CWE-787 - Out-of-bounds write

CVSSv4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to an out-of-bounds write in the Linux kernel IPTFS function iptfs_reassem_cont() when reassembling an inner IP packet whose declared length is smaller than its minimum header size. A remote attacker can send specially crafted outer packets that split the inner IPv4 header across two packets and declare an inner total length between 6 and 19 bytes to cause a denial of service.

Remote exploitation targets IPTFS VPN gateways and requires the decrypted outer socket buffer to be linear, as can occur with AF_PACKET taps or tun/tap delivery. The socket buffer tailroom check triggers a kernel panic.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/5b8afb56ccb7c014b0f1ac40341708b200443c2d
• https://git.kernel.org/stable/c/a7018ee0ea8622ed59edc064be4e0f2c26464f53
• https://git.kernel.org/stable/c/dc33262be1fe43d0eb0b84fb58c6ed42e2f64a8c