CVE-2026-98241: Linux Vulnerability (CVSS 7.8)

Description

In the Linux kernel, the following vulnerability has been resolved: ipv6: xfrm: use full sockets in local error paths xfrm6_local_rxpmtu() and xfrm6_local_error() dereference skb->sk as if it always pointed at a full IPv6 socket. That is not guaranteed. TCP SYN-ACK skbs can be owned by a TCP_NEW_SYN_RECV request_sock while the output path itself is driven by the full listener. If rerouting selects an IPv6 XFRM tunnel route with a lower MTU, the local PMTU/error handling path can reach these callbacks with that mini-socket still attached to the skb. The callbacks then miscast the request socket as a full inet/IPv6 socket and can read beyond the request_sock allocation when they access inet_sock or ipv6_pinfo state. Resolve the owner with skb_to_full_sk() in both callbacks and bail out when no full socket is attached. This matches the surrounding XFRM IPv6 PMTU/error logic, which already reasons about full sockets with skb_to_full_sk().

Metrics

CVSS 3.1

7.8/10

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

EPSS Probability

0.18%

7.3th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

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

Vendor	Product	Versions
Linux	Linux	>= dd767856a36e00b631d65ebc4bb81b19915532d6, < b1a88633c36d2cbc3831382f3846754d344276fd; >= dd767856a36e00b631d65ebc4bb81b19915532d6, < 904a0e827d0d7189271a3a2eb648293809f25efc; >= dd767856a36e00b631d65ebc4bb81b19915532d6, < 675919e08ce266b8cac11fd9af29170e762a480f; >= dd767856a36e00b631d65ebc4bb81b19915532d6, < 60459c670329d586a58db5d8f811fa5accfe4862; >= dd767856a36e00b631d65ebc4bb81b19915532d6, < ca3d68c3213475b53db6647e159dc73bd1af5ab1; >= dd767856a36e00b631d65ebc4bb81b19915532d6, < 4c030a0400ebfd2318361c923a88103b2c67c49f; >= dd767856a36e00b631d65ebc4bb81b19915532d6, < c21f3f7fbfeda7c5794f606cb0ffcc2d9001eef8; >= dd767856a36e00b631d65ebc4bb81b19915532d6, < 6973a21ee73c5567f883813c8ef414774b45892f
Linux	Linux	3.2

References

Timeline

Published: Oct 6, 2026
Last Modified: Oct 7, 2026
Status: Received

Frequently Asked Questions

What is CVE-2026-98241?

In the Linux kernel, the following vulnerability has been resolved: ipv6: xfrm: use full sockets in local error paths xfrm6_local_rxpmtu() and xfrm6_local_error() dereference skb->sk as if it always pointed at a full IPv6 socket. That is not guaranteed. TCP SYN-ACK skbs can be owned by a TCP_NEW_SYN_RECV request_sock while the output path itself is driven by the full listener. If rerouting selects an IPv6 XFRM tunnel route with a lower MTU, the local PMTU/error handling path can reach these callbacks with that mini-socket still attached to the skb. The callbacks then miscast the request socket as a full inet/IPv6 socket and can read beyond the request_sock allocation when they access inet_sock or ipv6_pinfo state. Resolve the owner with skb_to_full_sk() in both callbacks and bail out when no full socket is attached. This matches the surrounding XFRM IPv6 PMTU/error logic, which already reasons about full sockets with skb_to_full_sk().

How severe is CVE-2026-98241?

CVE-2026-98241 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.18% probability of exploitation in the next 30 days.

How do I fix CVE-2026-98241?

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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