CVE-2026-90156: ksmbd: safely discard unregistered deferred locks
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 054bcca4cd9f00719b01f7108b51a2168fb94f15, 52b91bc5253bb83665f3ea70565d0b2487dae643, 77413400f083a959724de6f36348c9677ef9873a; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes.
Low priority for now. Upgrade to Linux Linux 054bcca4cd9f00719b01f7108b51a2168fb94f15, 52b91bc5253bb83665f3ea70565d0b2487dae643, 77413400f083a959724de6f36348c9677ef9873a; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes 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: safely discard unregistered deferred locks When vfs_lock_file() defers a lock, smb2_lock() puts its ksmbd_lock on rollback_list before allocating and registering the asynchronous work. If either operation fails, rollback assumes that smb_lock->conn is initialized and dereferences NULL. The deferred file_lock also remains linked into the VFS blocked-lock state while it is freed. Keep the lock off rollback_list until async setup succeeds. On setup failures, explicitly unblock and wake the deferred lock before freeing it and its ksmbd wrapper.
- 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.
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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 aaa51ac0d934cb4e2ab96e150fccc934e822009baffected · git
- e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and later · before ecdcfa15b3d799476c685cecd433ebefc93015c8affected · git
- e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and later · before 77413400f083a959724de6f36348c9677ef9873aaffected · git
- e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and later · before 52b91bc5253bb83665f3ea70565d0b2487dae643affected · git
- e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and later · before d09af9a35ff7b77a950b507133d9092aadbfeff4affected · git
- e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and later · before 054bcca4cd9f00719b01f7108b51a2168fb94f15affected · 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 |
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-2026-90154Sep 17, 2026 · ksmbd: scope session state changes to bound connections0Monitor
- ← EarlierCVE-2026-90155Sep 17, 2026 · ksmbd: detach blocked lock requests before freeing0Monitor
- Later →CVE-2026-90157Sep 17, 2026 · bpf: Reject negative optlen in cgroup getsockopt hook0Monitor
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 | 054bcca4cd9f00719b01f7108b51a2168fb94f15 | Vendor (CNA) |
| Linux Linux | 52b91bc5253bb83665f3ea70565d0b2487dae643 | Vendor (CNA) |
| Linux Linux | 77413400f083a959724de6f36348c9677ef9873a | Vendor (CNA) |
| Linux Linux | aaa51ac0d934cb4e2ab96e150fccc934e822009b | Vendor (CNA) |
| Linux Linux | d09af9a35ff7b77a950b507133d9092aadbfeff4 | Vendor (CNA) |
| Linux Linux | ecdcfa15b3d799476c685cecd433ebefc93015c8 | Vendor (CNA) |
| azl3 kernel 6.6.150.1-1 on Azure Linux 3.0 | — | Microsoft (MSRC) |
| azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 | Release Notes | Microsoft (MSRC) |
| azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 | Release Notes | Microsoft (MSRC) |
| azl3 kernel 6.6.159.1-1 on Azure Linux 3.0 | Release Notes | Microsoft (MSRC) |
| debian:linux | 6.12.115-2 · Debian:13 | Package registry (OSV) |
| debian:linux | 7.2.6-1 · 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.
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/52b91bc5253bb83665f3ea70565d0b2487dae643
- git.kernel.org/stable/c/77413400f083a959724de6f36348c9677ef9873a
- git.kernel.org/stable/c/aaa51ac0d934cb4e2ab96e150fccc934e822009b
- git.kernel.org/stable/c/d09af9a35ff7b77a950b507133d9092aadbfeff4
- git.kernel.org/stable/c/ecdcfa15b3d799476c685cecd433ebefc93015c8
Vendor advisories and official records. Exploit/PoC links are deliberately left out.