Vulnerability in Linux

CVE-2026-53363

In the Linux kernel, the following vulnerability has been resolved: xfrm: iptfs: preserve shared-frag marker in iptfs_consume_frags() iptfs_consume_frags() transfers paged fragments from one socket buffer to another but fails to propagate the SKBFL_SHARED_FRAG flag. This is the same class of bug that was fixed in skb_try_coalesce() for CVE-2026-46300: when fragments backed by read-only page-cache pages are merged, the marker indicating their shared nature must be preserved so that ESP can decide correctly whether in-place encryption is safe. Apply the same two-line fix used in skb_try_coalesce() to iptfs_consume_frags().

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.003 (22.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 23rd percentile — 22.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-53363: held from 0.004 to 0.003.

EPSS over last 30 days · oldest: 0.004 · newest: 0.003 · change: -0.001

Affected products

  • Linux — versions b96ba312e21c9b7ac1526829b9640ddc06695c0b, 6.14, 0
  • Linux Kernel — versions 7.1

References

Frequently asked questions

What is CVE-2026-53363?
CVE-2026-53363 is a critical-severity vulnerability in Linux. CVSS score: 9.8/10. Published 2026-07-10.
How severe is CVE-2026-53363?
Critical severity. CVSS v3 base score is 9.8 out of 10.