# CVE-2026-53363: linux: In the Linux kernel, the following vulnerability has been resolved:  xfrm: iptfs: preserve shared-frag marker in iptf...

CVE-2026-53363 is fixed in linux on 1 platform by DEBIAN-CVE-2026-53363 (version 7.0.13-1), released July 10, 2026. It is not reported as exploited. Patch Radar priority: Urgent.

- Web page: https://patchblox.com/security/cve/CVE-2026-53363
- Priority: Urgent
- CVSS: 9.8 (critical)
- EPSS: 0.0041
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jul 10, 2026

## 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().

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 14 | 7.0.13-1 | [DEBIAN-CVE-2026-53363](https://patchblox.com/security/data/fix/linux/debian-cve-2026-53363.md) | Jul 10, 2026 |

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Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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