CVE-2026-98950

What it is

In the Linux kernel, the following vulnerability has been resolved: flow_dissector: avoid u16 truncation of hlen in bpf_flow_dissect() bpf_flow_dissect() sanitizes the offsets returned by the BPF program with clamp_t(u16, ..., hlen). If hlen is bigger than 65535, the upper bound is truncated before the comparison. For instance, with hlen == 65536, both nhoff and thoff are forced to zero, even if the program returned sane values. This is the same class of bug as the one fixed in commit 99bda1ecbd56 ("flow_dissector: avoid u16 truncation of skb->len when computing thoff"). That fix does not cover the BPF path, because __skb_flow_dissect() returns early when a BPF flow dissector handles the packet. struct bpf_flow_keys stores nhoff and thoff as u16, so cap hlen to U16_MAX before clamping. Found by sashiko while reviewing the commit above.

At a glance

Exploit odds

0.2% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-10-23 13:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-30 13:21 UTC Last updatedMost recent change to the record

Details

Published

2026-10-23 13:17 UTC

Last modified

2026-10-30 13:21 UTC

Exploit probability

0.2% · EPSS, next 30 days

Record status

Received