CVE-2026-89745
Published Sep 11, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: debugfs: Fix lockdown check for mmap_prepare Commit 651fdda8406d ("relay: update relay to use mmap_prepare") changed the `mmap` file operation to `mmap_prepare` for relayfs, but the lockdown check in debugfs was not updated accordingly. This prevents debugfs from being locked down when the kernel is in integrity mode if a file uses `mmap_prepare` but not `mmap`. Since the conversion to `mmap_prepare` across the kernel is not yet complete, update the lockdown check to look for both `mmap` and `mmap_prepare` to ensure comprehensive coverage.
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References
Frequently Asked Questions
What is CVE-2026-89745? +
In the Linux kernel, the following vulnerability has been resolved:
debugfs: Fix lockdown check for mmap_prepare
Commit 651fdda8406d ("relay: update relay to use mmap_prepare")
changed the `mmap` file operation to `mmap_prepare` for relayfs, but
the lockdown check in debugfs was not updated accordingly.
This prevents debugfs from being locked down when the kernel is in
integrity mode if a file uses `mmap_prepare` but not `mmap`.
Since the conversion to `mmap_prepare` across the kernel is not yet
complete, update the lockdown check to look for both `mmap` and
`mmap_prepare` to ensure comprehensive coverage.
How do I check if I'm vulnerable to CVE-2026-89745? +
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.