CVE-2026-53228
Linux Kernel vulnerability
- Published25 Jun 2026
Description
In the Linux kernel, the following vulnerability has been resolved: ipv6: sit: reload inner IPv6 header after GSO offloads ipip6_tunnel_xmit() caches the inner IPv6 header pointer at function entry and continues using it after iptunnel_handle_offloads(). For GSO skbs, iptunnel_handle_offloads() calls skb_header_unclone(). When the skb header is cloned, skb_header_unclone() can call pskb_expand_head(), which may move the skb head. The pskb_expand_head() contract requires pointers into the skb header to be reloaded after the call. If the later skb_realloc_headroom() branch is not taken, SIT uses the stale iph6 pointer to read the inner hop limit and DS field. That can read from a freed skb head after the old head's remaining clone is released. Reload iph6 after the offload helper succeeds and before subsequent reads from the inner IPv6 header. Keep the existing reload after skb_realloc_headroom(), since that branch can also replace the skb.
CVSS 3.1 breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HAffected products
Remediation
- https://git.kernel.org/stable/c/0bfa7bba1f41aaf5f0604dc712bb4701493e3aa0
- https://git.kernel.org/stable/c/1132e5edc2866c3530be17622153a597095f0e43
- https://git.kernel.org/stable/c/2fa49b2715e1bad12ce3b0fa64e234d9582c8193
- https://git.kernel.org/stable/c/59f80c919713250fe5d25a4d9aea4e49580fa1d4
- https://git.kernel.org/stable/c/9c67b44edb3598d234efae6e44649eb993c03da5
- https://git.kernel.org/stable/c/cb658c2f5f7977c2a1c77c9f239f4bc8196edb5c
References
- https://git.kernel.org/stable/c/0bfa7bba1f41aaf5f0604dc712bb4701493e3aa0
- https://git.kernel.org/stable/c/1132e5edc2866c3530be17622153a597095f0e43
- https://git.kernel.org/stable/c/2fa49b2715e1bad12ce3b0fa64e234d9582c8193
- https://git.kernel.org/stable/c/59f80c919713250fe5d25a4d9aea4e49580fa1d4
- https://git.kernel.org/stable/c/9c67b44edb3598d234efae6e44649eb993c03da5
- https://git.kernel.org/stable/c/cb658c2f5f7977c2a1c77c9f239f4bc8196edb5c
- https://git.kernel.org/stable/c/f0e42f0c4337b1f220de1ddd63f47197c7dee4de
- https://git.kernel.org/stable/c/fddd41445a0537b093e6b3f6232c9933cad1e48b
Frequently asked
Is CVE-2026-53228 being actively exploited?
CVE-2026-53228 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.51%.
How severe is CVE-2026-53228?
CVE-2026-53228 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 0.51% probability of exploitation.
Which products are affected by CVE-2026-53228?
Affected products include Linux Kernel.
How do I fix CVE-2026-53228?
Upgrade affected software to a fixed version, for example Linux Kernel 5.10.259 or later, then confirm no affected versions remain in your inventory.
How Secuno handles this
Secuno correlates vulnerabilities like CVE-2026-53228 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.
Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.