CVE-2026-64392 — In the Linux kernel, the following vulnerability has been resolved: ksmbd: use opener…
In the Linux kernel, the following vulnerability has been resolved: ksmbd: use opener credentials for delete-on-close Delete-on-close can be completed by deferred or durable handle teardown, where no request work is available. Both the base-file unlink and the ADS xattr removal consequently run with the ksmbd worker credentials and can bypass filesystem permission checks. Run both operations with the credentials captured in struct file when the handle was opened. This preserves the authenticated user's fsuid, fsgid, supplementary groups and capability restrictions at final close.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- Technical severity (critical)+10
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux Kernel).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux Kernel | ≥ 5.15 and < 6.6.145≥ 6.7 and < 6.12.96≥ 6.13 and < 6.18.39≥ 6.19 and < 7.1.4 | Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 9.1 | CVSS 3.1 | Critical | 3.9 | 5.2 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67) Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Timeline
What happened to this CVE, newest first.
- 2026
- Record published
- Fix documented
- CVSS changed · 9.1
- Source status changed · → Analyzed
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
5 on the record
- git.kernel.org/stable/c/4b7059974549d278e30fe70e2a4e421f9839817d
- git.kernel.org/stable/c/52e2f21911158ec961cd5aae19c56460db382af0
- git.kernel.org/stable/c/f08b3f451f12eee4abd8a5981803bc36db84458b
- git.kernel.org/stable/c/e72c15085b6d86f45d224d98aa75b5cace4aaab9
- git.kernel.org/stable/c/18c59109bb6fb816d5102171666f87cf1e29901d
Elsewhere on this site
Related CVEs (same products)
- Medium CVE-2026-98164 KVM: x86/mmu: Check write tracking in all address spaces 16d
- High CVE-2026-98163 cgroup: Avoid iteration of dying tasks with zero refcount 19d
- Medium CVE-2026-98162 smb/server: fix tree connection leak in smb2_tree_connect() 20d
- Medium CVE-2026-98160 staging: rtl8723bs: fix mismatched free of HalData in rtw_sdio_if1_init() 20d
- Medium CVE-2026-98161 Improper Check for Unusual or Exceptional Conditions in Linux Linux Kernel 20d
- Medium CVE-2026-100079 usb: typec: ucsi: unregister debugfs entries on teardown 20d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No FIRST EPSS score.
- No CISA SSVC assessment.
- No CWE classification.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-64392 is "In the Linux kernel, the following vulnerability has been resolved: ksmbd: use opener…", rated Critical. It affects Linux Kernel (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 9.1 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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