CVE-2026-90167: ksmbd: serialize oplock close with pending break ownership
Noroxi assessment
Priority: Monitor (action score 0/100)
- 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: 0.21% (FIRST EPSS).
- Fixed version: Linux Linux 02a31a30ccd09f3ff35ab5861c04209c381aa5dd, 5f97bac88bfb333f426f01c118b8235e75af8d96, 7148a6c06ddf1c263a1cf422bee541f24d3d3926.
Low priority for now. Upgrade to Linux Linux 02a31a30ccd09f3ff35ab5861c04209c381aa5dd, 5f97bac88bfb333f426f01c118b8235e75af8d96, 7148a6c06ddf1c263a1cf422bee541f24d3d3926 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: serialize oplock close with pending break ownership close may abort an in-flight oplock break while another breaker already holds an opinfo reference. Releasing pending_break wakes that waiter, but without serializing the close transition with bit acquisition it can become a new break owner through the test_and_set_bit() fast path. It can then overwrite OPLOCK_CLOSING with OPLOCK_ACK_WAIT and continue a break for a dying opinfo. Make OPLOCK_CLOSING terminal once the opinfo is removed from the inode list. Serialize that transition, pending_break acquisition, and OPLOCK_ACK_WAIT setup with an opinfo state lock. A breaker which loses the race releases its ownership and returns -ENOENT. Explicitly wake pending_break waiters during close so they can observe the terminal state. Also prevent ACK and timeout paths from replacing OPLOCK_CLOSING with OPLOCK_STATE_NONE.
- Published
- Sep 17, 2026
- Updated
- Oct 30, 2026
- EPSS
- 0.2% · 11th percentile
- CWE
- —
Report tools
Action score
0
Monitor
Low priority for now.
- CVSS
- 0 / 40 · —
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
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
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected 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.
—
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
- 5.15affected
- e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and later · before 02a31a30ccd09f3ff35ab5861c04209c381aa5ddaffected · git
- e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and later · before 7148a6c06ddf1c263a1cf422bee541f24d3d3926affected · git
- e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and later · before 7d6e682b7633120c2f93400b8c6f335d9d8e5318affected · git
- e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and later · before dc1e34f78dfab755fab9ad820ac5f82348fe1792affected · git
- e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and later · before 5f97bac88bfb333f426f01c118b8235e75af8d96affected · git
- e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and later · before b0148dc5625dbfd50596ac63c7487c12e8a8ab03affected · git
- before 5.15not affected · semver
- 6.1.191 and later · up to and including 6.1.*not affected · semver
- 6.6.160 and later · up to and including 6.6.*not affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | linux | from 0 | — |
| Debian:13 | linux | before 6.12.115-2 | 6.12.115-2 |
| Debian:14 | linux | before 7.2.6-1 | 7.2.6-1 |
| openSUSE:Tumbleweed | kernel-source | before 7.2.8-1.1 | 7.2.8-1.1 |
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation40Plan
- CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment40Plan
- CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()40Plan
Published before and after this one in the same product
- ← EarlierCVE-2026-90165Sep 17, 2026 · smb/server: fix invalid pointer dereference in ksmbd_stop_durable_scavenger()0Monitor
- ← EarlierCVE-2026-90166Sep 17, 2026 · smb/server: fix null-ptr-deref in ksmbd_ipc_tree_connect_request()0Monitor
- Later →CVE-2026-90169Sep 17, 2026 · ksmbd: free preauth sessions on connection teardown0Monitor
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 | 02a31a30ccd09f3ff35ab5861c04209c381aa5dd | Vendor (CNA) |
| Linux Linux | 5f97bac88bfb333f426f01c118b8235e75af8d96 | Vendor (CNA) |
| Linux Linux | 7148a6c06ddf1c263a1cf422bee541f24d3d3926 | Vendor (CNA) |
| Linux Linux | 7d6e682b7633120c2f93400b8c6f335d9d8e5318 | Vendor (CNA) |
| Linux Linux | b0148dc5625dbfd50596ac63c7487c12e8a8ab03 | Vendor (CNA) |
| Linux Linux | dc1e34f78dfab755fab9ad820ac5f82348fe1792 | Vendor (CNA) |
| debian:linux | 6.12.115-2 · Debian:13 | Package registry (OSV) |
| debian:linux | 7.2.6-1 · Debian:14 | Package registry (OSV) |
| opensuse:kernel-source | 7.2.8-1.1 · openSUSE:Tumbleweed | 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.
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 researchersFinders, 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.
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Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
No CVSS vector for this record, so attack conditions can't be derived.
Weakness class (CWE)
—
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✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (5 more)Show less
- git.kernel.org/stable/c/5f97bac88bfb333f426f01c118b8235e75af8d96
- git.kernel.org/stable/c/7148a6c06ddf1c263a1cf422bee541f24d3d3926
- git.kernel.org/stable/c/7d6e682b7633120c2f93400b8c6f335d9d8e5318
- git.kernel.org/stable/c/b0148dc5625dbfd50596ac63c7487c12e8a8ab03
- git.kernel.org/stable/c/dc1e34f78dfab755fab9ad820ac5f82348fe1792
Vendor advisories and official records. Exploit/PoC links are deliberately left out.