CVE-2026-63800
Published Jul 19, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: pNFS: Fix use-after-free in pnfs_update_layout() When hitting the NFS_LAYOUT_RETURN branch in pnfs_update_layout(), the code calls pnfs_prepare_to_retry_layoutget(lo). If it succeeds, pnfs_put_layout_hdr(lo) is called before trace_pnfs_update_layout(), which still references 'lo'. This results in a use-after-free when the tracepoint accesses lo's fields. Fix this by moving the tracepoint call before pnfs_put_layout_hdr(lo).
Is your site exposed to CVE-2026-63800?
Run a free security scan — no signup, results in seconds.
References
Other References
https://git.kernel.org/stable/c/13e198a90ca4050f4bee8a3f23680389a6563ccc
https://git.kernel.org/stable/c/1f24b8302c77dcaf79c64c073877a3b9f4dd25d2
https://git.kernel.org/stable/c/200e7637f4d6a1342987045eea72641524f909dc
https://git.kernel.org/stable/c/2883ddd7542b4437a2ab4908fe2773f690e20889
https://git.kernel.org/stable/c/4ad8b9a85dbf57ca532ee9e65ad7e6498bfbbf98
https://git.kernel.org/stable/c/7e37e9b3e82ade881e1798e2f4fcc54aff7793c1
https://git.kernel.org/stable/c/9645aaf689aff57427ece3b9fa47d5b5399417f4
https://git.kernel.org/stable/c/9c0fb5c09ae5bd68dc0038692af8127029cb0385
Frequently Asked Questions
What is CVE-2026-63800? +
In the Linux kernel, the following vulnerability has been resolved:
pNFS: Fix use-after-free in pnfs_update_layout()
When hitting the NFS_LAYOUT_RETURN branch in pnfs_update_layout(),
the code calls pnfs_prepare_to_retry_layoutget(lo). If it succeeds,
pnfs_put_layout_hdr(lo) is called before trace_pnfs_update_layout(),
which still references 'lo'. This results in a use-after-free when the
tracepoint accesses lo's fields.
Fix this by moving the tracepoint call before pnfs_put_layout_hdr(lo).
How do I check if I'm vulnerable to CVE-2026-63800? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.