CVE-2026-23428: In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free of share_conf i

Q: How do I fix CVE-2026-23428?

linux kernel: upgrade to 5.15.203, 6.1.167, 6.4, 6.6.130, 6.12.78, 6.18.20, 6.19.10. Exact commands for each OS are on this page.

Q: Is CVE-2026-23428 being exploited?

CVE-2026-23428 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-23428 affect?

CVE-2026-23428 affects linux kernel. Severity is critical (CVSS 9.8). In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free of share_conf in compound request smb2_get_ksmbd_tcon() reuses work->tcon in compound requests without validating tcon->t_state. ksmbd_tree_conn

This month

CRITICAL 9.8REMOTEWATCHLISTUPGRADE

CVE-2026-23428 is a critical-severity flaw (CVSS 9.8) affecting linux kernel. 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: ksmbd: fix use-after-free of share_conf in compound request smb2_get_ksmbd_tcon() reuses work->tcon in compound requests without validating tcon->t_state. ksmbd_tree_conn_lookup() checks t_state == TREE_CONNECTED on the initial lookup path, but the compound reuse path bypasses this check entirely. If a prior command in the compound (SMB2_TREE_DISCONNECT) sets t_state to TREE_D

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	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 74%)
CISA exploited list	No
Weakness	CWE-416
Published	2026-04-03
Last modified	2026-10-19

Publisher (CNA): kernel.org · Vendor: linux

Last updated 2026-10-19 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-03 16:16 UTCPublished CVE record published
2026-10-19 19:17 UTCUpdated Record last modified

linux linux kernel UPGRADE

Affected: >= 5.15.121 and < 5.15.203 · >= 6.1.36 and < 6.1.167 · >= 6.3.10 and < 6.4 · >= 6.4.1 and < 6.6.130 · >= 6.7 and < 6.12.78 · >= 6.13 and < 6.18.20 · >= 6.19 and < 6.19.10 · 6.4

Fixed in: 5.15.203, 6.1.167, 6.4, 6.6.130, 6.12.78, 6.18.20, 6.19.10

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

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-2026-23428?

linux kernel: upgrade to 5.15.203, 6.1.167, 6.4, 6.6.130, 6.12.78, 6.18.20, 6.19.10. Exact commands for each OS are on this page.

Is CVE-2026-23428 being exploited?

CVE-2026-23428 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-2026-23428 affect?

CVE-2026-23428 affects linux kernel. Severity is critical (CVSS 9.8). In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free of share_conf in compound request smb2_get_ksmbd_tcon() reuses work->tcon in compound requests without validating tcon->t_state. ksmbd_tree_conn

How urgent is CVE-2026-23428?

Priority 51/100. Critical severity; Remotely exploitable, no login, no user action; On your watchlist

Software pages

Linux kernel vulnerabilities

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References

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