CVE-2026-53363: Linux kernel · xfrm: iptfs: preserve shared-frag marker in iptfs_consume_frags()
Source GCVE Database
Mentioned vulnerabilities
Not known to be exploited · CVSS 9.8 Critical.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 35% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 10 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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
AI-suggested
A fix has been applied to the Linux kernel source code to preserve the SKBFL_SHARED_FRAG flag in iptfs_consume_frags(), similar to the fix for CVE-2026-46300. Users and administrators should update their Linux kernel to a version that includes this fix. Patch status is not explicitly stated in the provided data; therefore, check the official Linux kernel advisories or vendor updates for the exact fixed versions and apply the update accordingly.
Description
A critical vulnerability in the Linux kernel's xfrm subsystem was resolved involving the iptfs_consume_frags() function. This function failed to preserve the SKBFL_SHARED_FRAG flag when transferring paged fragments between socket buffers. The missing flag propagation can lead to incorrect handling of shared fragments, affecting the security of in-place encryption decisions in ESP. The issue is similar to a previously fixed bug (CVE-2026-46300) and was addressed by applying the same fix to preserve the shared-frag marker.
References
- nvd.nist.gov/vuln/detail/CVE-2026-53363 (opens in a new tab)
- git.kernel.org/stable/c/c885d111ed9f5a0a1f3cc4e87a50db6518abaa6c (opens in a new tab)
- git.kernel.org/stable/c/dd66f7f6e360ee82cd905517726f8e9091265de5 (opens in a new tab)
- git.kernel.org/stable/c/e9096a5a170e7ecd6467bc2e08668ec39897cda7 (opens in a new tab)