Improper input validation in Linux kernel - CVE-2026-63819

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Main Vulnerability Database Vulnerabilities #VU138843

Improper input validation in Linux kernel - CVE-2026-63819

Published: July 21, 2026


Vulnerability identifier: #VU138843
CSH Severity: Low
CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-63819
CWE-ID: CWE-20
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to improper input validation in f2fs_get_node_folio_ra() when processing a corrupted f2fs inode during filesystem mount and inode truncation. A local user can supply a crafted corrupted f2fs image to trigger a kernel panic and cause a denial of service.

The issue is triggered by an inconsistent node chain in the inode mapping table where a direct node has the same ino and nid in its footer, leading to a bug check in f2fs_do_truncate_blocks().


Affected software

Linux kernel
Ubuntu
linux-nvidia-tegra (Ubuntu package)
linux (Ubuntu package)
linux-realtime (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-aws (Ubuntu package)
linux-raspi (Ubuntu package)
linux-azure (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-ibm (Ubuntu package)
linux-nvidia-bos (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
linux-oracle-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-gke (Ubuntu package)
linux-aws-7.0 (Ubuntu package)
linux-nvidia-7.0 (Ubuntu package)

How to mitigate CVE-2026-63819

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux-nvidia-tegra (Ubuntu package) - update to 6.8.0-1036.39
linux (Ubuntu package) - update to 7.0.0-31.31
linux-realtime (Ubuntu package) - update to 7.0.0-31.31.1
linux-gcp (Ubuntu package) - update to 7.0.0-1011.11
linux-oracle (Ubuntu package) - update to 7.0.0-1011.11
linux-aws (Ubuntu package) - update to 7.0.0-1012.12
linux-raspi (Ubuntu package) - update to 7.0.0-1019.19
linux-azure (Ubuntu package) - update to 7.0.0-1014.14
linux-nvidia (Ubuntu package) - update to 7.0.0-1018.18
linux-ibm (Ubuntu package) - update to 7.0.0-1013.13
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2018.18
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-31.31~24.04.1
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-azure-7.0 (Ubuntu package) - update to 7.0.0-1014.14~24.04.1
linux-oracle-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1013.13
linux-gke (Ubuntu package) - update to 7.0.0-1006.7
linux-aws-7.0 (Ubuntu package) - update to 7.0.0-1012.12~24.04.1
linux-nvidia-7.0 (Ubuntu package) - update to 7.0.0-1018.18~24.04.1

External References

Related Security Bulletins