CVE-2026-72248 — CRITICAL (9.8)

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: flowtable: support IPIP tunnel with direct xmit The combination of IPIP tunnel with direct xmit, eg. bridge device, breaks because no dst_entry is provided to check the skb headroom and to set the iph->frag_off field. This leads to invalid dst usage and can trigger a crash in the tunnel transmit path. Fix this by moving dst_cache and dst_cookie out of the runtime union so that they can be shared by neighbour, xfrm, and direct tunnel flows. For FLOW_OFFLOAD_XMIT_DIRECT tuples carrying tunnel metadata, preserve route state in these shared fields and release it through the common dst release path. Since dst_entry is now available to the three supported xmit modes and dst_release() already deals with NULL dst, remove the xmit type check in nft_flow_dst_release(). Moreover, skip the check if the dst entry is NULL in nf_flow_dst_check() which is now the case for the direct xmit case. Based on patch from Rein Wei <[email protected]>.

CVSS Score

9.8

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

HIGH

Integrity

HIGH

Availability

HIGH

References

FAQ

What is CVE-2026-72248?

CVE-2026-72248 is a vulnerability with a CVSS score of 9.8 (CRITICAL). In the Linux kernel, the following vulnerability has been resolved: netfilter: flowtable: support IPIP tunnel with direct xmit The combination of IPIP tunnel with direct xmit, eg. bridge device, bre...

How severe is CVE-2026-72248?

CVE-2026-72248 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.

Is there a patch for CVE-2026-72248?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.