CVE-2026-53363 xfrm: iptfs: preserve shared-frag marker in iptfs_consume_frags()

What is CVE-2026-53363?

CVE-2026-53363 is a critical memory corruption vulnerability in Linux kernel, published on 10 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

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().

Which versions are affected by CVE-2026-53363?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-53363?

Apply the vendor's patch.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2026-53363 being exploited?

There is no known exploitation of CVE-2026-53363 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BELL-CVE-2026-53363, DEBIAN-CVE-2026-53363, GHSA-7xf9-r6gc-x4cm, UBUNTU-CVE-2026-53363.