NVD / CVE Program· CNA Linux

CVE-2026-64016: ksmbd: fix durable reconnect error path file lifetime

Noroxi assessment

Priority: Monitor (action score 39/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.67% (FIRST EPSS); higher than 52% of all records.
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
Fixed version: Linux Linux 3515503322f4819277091839eed46b695096aca5, 478bfaa036bd0c7e179acff8b8484bccdee3b8c7, 5e641e4ee0bc1937408d41051a908ad4151be63b.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 3515503322f4819277091839eed46b695096aca5, 478bfaa036bd0c7e179acff8b8484bccdee3b8c7, 5e641e4ee0bc1937408d41051a908ad4151be63b or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix durable reconnect error path file lifetime After a durable reconnect succeeds, ksmbd_reopen_durable_fd() republishes the same ksmbd_file into the session volatile-id table. If smb2_open() then takes a later error path, cleanup first calls ksmbd_fd_put(work, fp) and then unconditionally calls ksmbd_put_durable_fd(dh_info.fp). In this case fp and dh_info.fp are the same object. The first put drops the reconnect lookup reference, but the final durable put can run __ksmbd_close_fd(NULL, fp). Because the final close is not session-aware, it can free the file object without removing the volatile-id entry that was just published into the session table. Use the session-aware put for the final reconnect drop when the reconnect had already succeeded and the error path is cleaning up the republished file. Earlier reconnect failures, before fp is assigned to dh_info.fp, keep using the durable-only put path.

CriticalCVSS 9.8 · v3.1—No exploit Fix available

EUVD-2026-45589

Published: Jul 19, 2026
Updated: Oct 13, 2026
EPSS: 0.6% · 52th percentile
CWE: CWE-416

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 39 / 40 · 9.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.6%

CNA vs NVD score

NVD: —
CNA · Linux: 9.8; NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
linux	linux kernel	cpe:2.3:o:linux:linux_kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

linux linux kernel6.18.33
linux linux kernel7.0.10
linux linux kernel7.1

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

Linux Linux
- f0ff7f12398e85b3a11745ff7feab6246f3d75c2 and later · before 5e641e4ee0bc1937408d41051a908ad4151be63baffected · git
- 4db3dcac84c2f14a45ae201efb38de1fb1bfc009 and later · before 478bfaa036bd0c7e179acff8b8484bccdee3b8c7affected · git
- ce2e164c1c51c3f7813b80f8c926836e896bcbb3 and later · before a1a39f227c80cbf369767badc32cba2b225147d1affected · git
- 97a0cd55283b4e63fd92804da91c8d9896adcad9 and later · before 6cb0b9385320110fe24a5d5ac0000ade4bb3a3f3affected · git
- 1baff47b81f94f9231c91236aa511420d0e266b9 and later · before 3515503322f4819277091839eed46b695096aca5affected · git
- 6.18.33 and later · before 6.18.34affected · semver
- 7.0.10 and later · before 7.0.11affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Debian:14	linux	before 7.0.12-1	7.0.12-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
90Now
CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
89Now
CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
85Now

Published before and after this one in the same product

← EarlierCVE-2026-64014Jul 19, 2026 · Input: usbtouchscreen - clamp NEXIO data_len/x_len to URB buffer size
28Monitor
← EarlierCVE-2026-64015Jul 19, 2026 · security/keys: fix missed RCU read section on lookup
31Monitor
Later →CVE-2026-64017Jul 19, 2026 · blk-mq: pop cached request if it is usable
31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
Linux Linux	3515503322f4819277091839eed46b695096aca5	Vendor (CNA)
Linux Linux	478bfaa036bd0c7e179acff8b8484bccdee3b8c7	Vendor (CNA)
Linux Linux	5e641e4ee0bc1937408d41051a908ad4151be63b	Vendor (CNA)
Linux Linux	6.18.34	Vendor (CNA)
Linux Linux	6cb0b9385320110fe24a5d5ac0000ade4bb3a3f3	Vendor (CNA)
Linux Linux	7.0.11	Vendor (CNA)
Linux Linux	a1a39f227c80cbf369767badc32cba2b225147d1	Vendor (CNA)
debian:linux	7.0.12-1 · Debian:14	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days+1% in 7 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

TR-26-0576 · Jul 20, 2026(Linux Kernel Güvenlik Bildirimi)

All national notices →

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

nvd-secondary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

Fix✗ → ✓Sep 28, 2026, 10:11 PM UTC

For records you follow, these changes also arrive as notifications. →

References

git.kernel.org/stable/c/3515503322f4819277091839eed46b695096aca5

Show all references (4 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records