CVE-2026-72248

CRITICALCVSS 9.8/10EPSS 0.19%

Last modified

CVE-2026-72248 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. 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. EPSS estimates a 0.19% chance of exploitation in the next 30 days.

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 <n05ec@lzu.edu.cn>.

Metrics

CVSS 3.1
9.8/10

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

EPSS Probability
0.19%

8.9th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
LinuxLinux>= d30301ba4b07ac92eb38353a111833b009003170, < 0880c4ed122d0cddc9f29a2b28f055d1f24f0fca; >= d30301ba4b07ac92eb38353a111833b009003170, < fa7395c02d95e51bad2952325d2d6503bfbad437
LinuxLinux6.19

References

Timeline

Published
Last Modified
Status
Received

Frequently Asked Questions

What is CVE-2026-72248?
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 <n05ec@lzu.edu.cn>.
How severe is CVE-2026-72248?
CVE-2026-72248 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 0.19% probability of exploitation in the next 30 days.
How do I fix CVE-2026-72248?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST