Skip to main content
VulnerabilityPublished Updated

CVE-2026-53228: Linux kernel · Use After Free

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 9.8 Critical · fixed in fddd41445a0537b093e6b3f6232c9933cad1e48b : patch Linux kernel as a priority.

Data as of 26 Oct 2026, 17:30 UTC

CVSS 3.1 base score
9.8Critical
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.5% chance of exploitation in 30 days – higher than 47% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers can reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in fddd41445a0537b093e6b3f6232c9933cad1e48b, f0e42f0c4337b1f220de1ddd63f47197c7dee4de, cb658c2f5f7977c2a1c77c9f239f4bc8196edb5c +5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 25 Jun 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ 14909664e4e192f4c6f6fcdccd9919af7cf783ab, < fddd41445a0537b093e6b3f6232c9933cad1e48b
Fixed in
  • fddd41445a0537b093e6b3f6232c9933cad1e48b
LinuxLinuxAffected
  • ≥ 14909664e4e192f4c6f6fcdccd9919af7cf783ab, < f0e42f0c4337b1f220de1ddd63f47197c7dee4de
Fixed in
  • f0e42f0c4337b1f220de1ddd63f47197c7dee4de
LinuxLinuxAffected
  • ≥ 14909664e4e192f4c6f6fcdccd9919af7cf783ab, < cb658c2f5f7977c2a1c77c9f239f4bc8196edb5c
Fixed in
  • cb658c2f5f7977c2a1c77c9f239f4bc8196edb5c
LinuxLinuxAffected
  • ≥ 14909664e4e192f4c6f6fcdccd9919af7cf783ab, < 1132e5edc2866c3530be17622153a597095f0e43
Fixed in
  • 1132e5edc2866c3530be17622153a597095f0e43
LinuxLinuxAffected
  • ≥ 14909664e4e192f4c6f6fcdccd9919af7cf783ab, < 59f80c919713250fe5d25a4d9aea4e49580fa1d4
Fixed in
  • 59f80c919713250fe5d25a4d9aea4e49580fa1d4
LinuxLinuxAffected
  • ≥ 14909664e4e192f4c6f6fcdccd9919af7cf783ab, < 9c67b44edb3598d234efae6e44649eb993c03da5
Fixed in
  • 9c67b44edb3598d234efae6e44649eb993c03da5

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.

References

Community reviews

Loading reviews…