CVE-2026-89713: In the Linux kernel, the following vulnerability has been resolved: NFSD: check truncate permission under ino

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CRITICAL 9.1REMOTEWATCHLIST

CVE-2026-89713 is a critical-severity flaw (CVSS 9.1) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In the Linux kernel, the following vulnerability has been resolved: NFSD: check truncate permission under inode lock nfsd_setattr() checks whether a size update needs NFSD_MAY_TRUNC before it takes inode_lock(). The comparison uses the file size sampled by that unlocked read, but the actual ATTR_SIZE update is applied later under inode_lock() by notify_change(). This leaves a TOCTOU window for append-only files. If a client sends a SETATTR tha

Why this priority

Critical severity
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	9.1 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 51%)
CISA exploited list	No
Published	2026-09-11
Last modified	2026-10-21

Publisher (CNA): kernel.org

Last updated 2026-10-21 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Timeline

2026-09-11 20:19 UTCPublished CVE record published
2026-10-21 13:20 UTCUpdated Record last modified

Exact fixes by distribution

Fedora 46 · fzssh · FIXED · 1.4.0-2.fc46 · FEDORA-2026-8004fcd067 · source

sudo dnf upgrade --advisory=FEDORA-2026-8004fcd067

Ubuntu 24.04 · linux · NO FIX YET

Ubuntu 22.04 · linux · NO FIX YET

Ubuntu 22.04 · linux-hwe-6.8 · NO FIX YET

Ubuntu 24.04 · linux-hwe-6.17 · NO FIX YET

Ubuntu 24.04 · linux-hwe-7.0 · NO FIX YET

Debian 12 · linux · NO FIX YET

Debian 13 · linux · FIXED · 6.12.111-1

sudo apt update && sudo apt install --only-upgrade linux dpkg --compare-versions "$(dpkg-query -W -f='${Version}' linux)" ge "6.12.111-1" && echo PATCHED || echo STILL-VULNERABLE

Debian 12 · linux-6.12 · FIXED · 6.12.111-1~deb12u1

sudo apt update && sudo apt install --only-upgrade linux-6.12 dpkg --compare-versions "$(dpkg-query -W -f='${Version}' linux-6.12)" ge "6.12.111-1~deb12u1" && echo PATCHED || echo STILL-VULNERABLE

RHEL 10 · kernel · NO FIX YET

RHEL 6 · kernel · NO FIX YET

RHEL 7 · kernel · NO FIX YET

RHEL 7 · kernel-rt · NO FIX YET

RHEL 8 · kernel · NO FIX YET

Amazon Linux 2023 · see advisory · FIXED · ALAS2023-2026-3196 · source

sudo dnf update --advisory=ALAS2023-2026-3196

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-89713?

No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.

Is CVE-2026-89713 being exploited?

CVE-2026-89713 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-89713 affect?

CVE-2026-89713 affects affected software. Severity is critical (CVSS 9.1). In the Linux kernel, the following vulnerability has been resolved: NFSD: check truncate permission under inode lock nfsd_setattr() checks whether a size update needs NFSD_MAY_TRUNC before it takes inode_lock(). The comparison uses the fi

How urgent is CVE-2026-89713?

Priority 54/100. Critical severity; Remotely exploitable, no login, no user action; On your watchlist

Software pages

Linux kernel vulnerabilities

References

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