ksmbd: fix null pointer dereference in alloc_preauth_hash()
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix null pointer dereference in alloc_preauth_hash() The Client send malformed smb2 negotiate request. ksmbd return error response. Subsequently, the client can send smb2 session setup even thought conn->preauth_info is not allocated. This patch add KSMBD_SESS_NEED_SETUP status of connection to ignore session setup request if smb2 negotiate phase is not complete.
- Published
- Apr 16, 2025
- Updated
- Aug 5, 2026
- EPSS
- 69.6% · 99th percentile
- CWE
- CWE-476
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Report tools
Action score
43
Plan
Add it to your regular patch cycle.
- CVSS
- 22 / 40 · 5.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 21 / 30 · 69.6%
CNA vs NVD score
- NVD
- 5.5
- CNA · Linux
- 7.5
- 2.0 point gap
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Affected systems
| 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 kernelbefore 6.12.23
- linux linux kernel6.13 and later · before 6.13.11
- linux linux kernel6.14 and later · before 6.14.2
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
- 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before cce57cd8c5dead24127cf2308fdd60fcad2d6ba6affected · git
- 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before ca8bed31edf728a662ef9d6f39f50e7a7dc2b5adaffected · git
- 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before 8f216b33a5e1b3489c073b1ea1b3d7cb63c8dc4daffected · git
- 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before b8eb243e670ecf30e91524dd12f7260dac07d335affected · git
- 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before c8b5b7c5da7d0c31c9b7190b4a7bba5281fc4780affected · git
- before 5.15not affected · semver
- 6.6.107 and later · up to and including 6.6.*not affected · semver
- 6.12.23 and later · up to and including 6.12.*not affected · semver
- 6.13.11 and later · up to and including 6.13.*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 | all versions | — |
| Debian:13 | linux | before 6.12.25-1 | 6.12.25-1 |
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- 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 KEV89Now
- CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV85Now
- CVE-2016-5195Race condition in mm/gup.c in the Linux kernel 2.x through 4.x before 4.8.3 allows local users to gain privileges by leveraging incorrect haKEV83Now
- CVE-2019-13272In the Linux kernel before 5.1.17, ptrace_link in kernel/ptrace.c mishandles the recording of the credentials of a process that wants to creKEV77This week
- CVE-2013-6282The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the v6k and v7 ARM platforms do not validate certain addKEV77This week
- CVE-2013-2094The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9 uses an incorrect integer data type, which allows loKEV77This week
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 | 8f216b33a5e1b3489c073b1ea1b3d7cb63c8dc4d | Vendor (CNA) |
| Linux Linux | b8eb243e670ecf30e91524dd12f7260dac07d335 | Vendor (CNA) |
| Linux Linux | c8b5b7c5da7d0c31c9b7190b4a7bba5281fc4780 | Vendor (CNA) |
| Linux Linux | ca8bed31edf728a662ef9d6f39f50e7a7dc2b5ad | Vendor (CNA) |
| Linux Linux | cce57cd8c5dead24127cf2308fdd60fcad2d6ba6 | Vendor (CNA) |
| Debian:linux | 6.12.25-1 · Debian:13 | 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.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-476 · NULL Pointer DereferenceCVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
nvd-primary
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.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- git.kernel.org/stable/c/8f216b33a5e1b3489c073b1ea1b3d7cb63c8dc4d
- git.kernel.org/stable/c/b8eb243e670ecf30e91524dd12f7260dac07d335
- git.kernel.org/stable/c/c8b5b7c5da7d0c31c9b7190b4a7bba5281fc4780
- git.kernel.org/stable/c/ca8bed31edf728a662ef9d6f39f50e7a7dc2b5ad
- git.kernel.org/stable/c/cce57cd8c5dead24127cf2308fdd60fcad2d6ba6
- www.zerodayinitiative.com/advisories/ZDI-25-310/
Vendor advisories and official records. Exploit/PoC links are deliberately left out.