CVE-2026-64379: smb: client: mask server-provided mode to 07777 in modefromsid
Noroxi assessment
Priority: Monitor (action score 28/100)
- 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: 0.30% (FIRST EPSS).
- Anyone who can reach it over the internet can trigger it. No account or password is required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
- Fixed version: Linux Linux 08c600b7e1818539ba5efee4cdb06215c245ca78, 5f6f2241034f189c69d4d0b5f8fe24a0c25b0c14, b84e002e0df26bbc6cbd3ca01b8212601fe0ae7d; azl3 kernel 6.6.144.1-1 on Azure Linux 3.0 6.6.145.2-1.
Low priority for now. Upgrade to Linux Linux 08c600b7e1818539ba5efee4cdb06215c245ca78, 5f6f2241034f189c69d4d0b5f8fe24a0c25b0c14, b84e002e0df26bbc6cbd3ca01b8212601fe0ae7d; azl3 kernel 6.6.144.1-1 on Azure Linux 3.0 6.6.145.2-1 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: smb: client: mask server-provided mode to 07777 in modefromsid When modefromsid is active, parse_dacl() applies the server-provided sub_auth[2] value from the NFS mode SID to cf_mode without masking to 07777. Apply the correct masking, same as in the read path.
- Published
- Jul 25, 2026
- Updated
- Oct 19, 2026
- EPSS
- 0.3% · 23th percentile
- CWE
- CWE-20
Report tools
Action score
28
Monitor
Low priority for now.
- CVSS
- 28 / 40 · 7.1 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.3%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · Linux
- 7.1
- 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
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.
| 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 kernel5.4 and later · before 5.10.261
- linux linux kernel5.11 and later · before 5.15.212
- linux linux kernel5.16 and later · before 6.1.178
- linux linux kernel6.2 and later · before 6.6.145
- linux linux kernel6.7 and later · before 6.12.96
- linux linux kernel6.13 and later · before 6.18.39
- linux linux kernel6.19 and later · before 7.1.4
- linux linux kernel7.2
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
- 5.4affected
- e2f8fbfb8d09c06decde162090fac3ee220aa280 and later · before 5f6f2241034f189c69d4d0b5f8fe24a0c25b0c14affected · git
- e2f8fbfb8d09c06decde162090fac3ee220aa280 and later · before ee2216dbdf0c677e89bb43e03247dba590ed00efaffected · git
- e2f8fbfb8d09c06decde162090fac3ee220aa280 and later · before f511807feee7cb29b61bdfa86472c7e9e2e5df94affected · git
- e2f8fbfb8d09c06decde162090fac3ee220aa280 and later · before 08c600b7e1818539ba5efee4cdb06215c245ca78affected · git
- e2f8fbfb8d09c06decde162090fac3ee220aa280 and later · before b84e002e0df26bbc6cbd3ca01b8212601fe0ae7daffected · git
- e2f8fbfb8d09c06decde162090fac3ee220aa280 and later · before c6c484a7d5bff6b929a86d7ed5130f29834c6a0daffected · git
- e2f8fbfb8d09c06decde162090fac3ee220aa280 and later · before f80add1bfb3425100a325b14f19648e75669a954affected · git
- e2f8fbfb8d09c06decde162090fac3ee220aa280 and later · before e3d9c7160d483fc8f9e225aafad8ecbbc43f3151affected · git
- before 5.4not affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:10 | kernel | before 6.12.0-211.49.1.el10_2 | 6.12.0-211.49.1.el10_2 |
| AlmaLinux:10 | kernel-64k | before 6.12.0-211.49.1.el10_2 | 6.12.0-211.49.1.el10_2 |
| AlmaLinux:10 | kernel-64k-core | before 6.12.0-211.49.1.el10_2 | 6.12.0-211.49.1.el10_2 |
| AlmaLinux:10 | kernel-64k-debug | before 6.12.0-211.49.1.el10_2 | 6.12.0-211.49.1.el10_2 |
| AlmaLinux:10 | kernel-64k-debug-core | before 6.12.0-211.49.1.el10_2 | 6.12.0-211.49.1.el10_2 |
| AlmaLinux:10 | kernel-64k-debug-devel | before 6.12.0-211.49.1.el10_2 | 6.12.0-211.49.1.el10_2 |
| AlmaLinux:10 | kernel-64k-debug-devel-matched | before 6.12.0-211.49.1.el10_2 | 6.12.0-211.49.1.el10_2 |
| AlmaLinux:10 | kernel-64k-debug-modules | before 6.12.0-211.49.1.el10_2 | 6.12.0-211.49.1.el10_2 |
| AlmaLinux:10 | kernel-64k-debug-modules-core | before 6.12.0-211.49.1.el10_2 | 6.12.0-211.49.1.el10_2 |
| AlmaLinux:10 | kernel-64k-debug-modules-extra | before 6.12.0-211.49.1.el10_2 | 6.12.0-211.49.1.el10_2 |
| AlmaLinux:10 | kernel-64k-devel | before 6.12.0-211.49.1.el10_2 | 6.12.0-211.49.1.el10_2 |
| AlmaLinux:10 | kernel-64k-devel-matched | before 6.12.0-211.49.1.el10_2 | 6.12.0-211.49.1.el10_2 |
| AlmaLinux:10 | kernel-64k-modules | before 6.12.0-211.49.1.el10_2 | 6.12.0-211.49.1.el10_2 |
| AlmaLinux:10 | kernel-64k-modules-core | before 6.12.0-211.49.1.el10_2 | 6.12.0-211.49.1.el10_2 |
| AlmaLinux:10 | kernel-64k-modules-extra | before 6.12.0-211.49.1.el10_2 | 6.12.0-211.49.1.el10_2 |
| AlmaLinux:10 | kernel-abi-stablelists | before 6.12.0-211.49.1.el10_2 | 6.12.0-211.49.1.el10_2 |
| AlmaLinux:10 | kernel-core | before 6.12.0-211.49.1.el10_2 | 6.12.0-211.49.1.el10_2 |
| AlmaLinux:10 | kernel-cross-headers | before 6.12.0-211.49.1.el10_2 | 6.12.0-211.49.1.el10_2 |
| AlmaLinux:10 | kernel-debug | before 6.12.0-211.49.1.el10_2 | 6.12.0-211.49.1.el10_2 |
| AlmaLinux:10 | kernel-debug-core | before 6.12.0-211.49.1.el10_2 | 6.12.0-211.49.1.el10_2 |
| AlmaLinux:10 | kernel-debug-devel | before 6.12.0-211.49.1.el10_2 | 6.12.0-211.49.1.el10_2 |
| AlmaLinux:10 | kernel-debug-devel-matched | before 6.12.0-211.49.1.el10_2 | 6.12.0-211.49.1.el10_2 |
| AlmaLinux:10 | kernel-debug-modules | before 6.12.0-211.49.1.el10_2 | 6.12.0-211.49.1.el10_2 |
| AlmaLinux:10 | kernel-debug-modules-core | before 6.12.0-211.49.1.el10_2 | 6.12.0-211.49.1.el10_2 |
+96
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV90Now
- 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
Published before and after this one in the same product
- ← EarlierCVE-2026-64377Jul 25, 2026 · cpufreq: qcom-cpufreq-hw: Fix possible double free31Monitor
- ← EarlierCVE-2026-64378Jul 25, 2026 · writeback: fix race between cgroup_writeback_umount() and inode_switch_wbs()31Monitor
- Later →CVE-2026-64380Jul 25, 2026 · smb: client: harden POSIX SID length parsing32Monitor
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 | 08c600b7e1818539ba5efee4cdb06215c245ca78 | Vendor (CNA) |
| Linux Linux | 5f6f2241034f189c69d4d0b5f8fe24a0c25b0c14 | Vendor (CNA) |
| Linux Linux | b84e002e0df26bbc6cbd3ca01b8212601fe0ae7d | Vendor (CNA) |
| Linux Linux | c6c484a7d5bff6b929a86d7ed5130f29834c6a0d | Vendor (CNA) |
| Linux Linux | e3d9c7160d483fc8f9e225aafad8ecbbc43f3151 | Vendor (CNA) |
| Linux Linux | ee2216dbdf0c677e89bb43e03247dba590ed00ef | Vendor (CNA) |
| Linux Linux | f511807feee7cb29b61bdfa86472c7e9e2e5df94 | Vendor (CNA) |
| Linux Linux | f80add1bfb3425100a325b14f19648e75669a954 | Vendor (CNA) |
| azl3 kernel 6.6.144.1-1 on Azure Linux 3.0 | 6.6.145.2-1 · CBL-Mariner Releases | Microsoft (MSRC) |
| almalinux:kernel | 6.12.0-211.49.1.el10_2 · AlmaLinux:10 | Package registry (OSV) |
| almalinux:kernel-64k | 6.12.0-211.49.1.el10_2 · AlmaLinux:10 | Package registry (OSV) |
| almalinux:kernel-64k-core | 6.12.0-211.49.1.el10_2 · AlmaLinux:10 | Package registry (OSV) |
| almalinux:kernel-64k-debug | 6.12.0-211.49.1.el10_2 · AlmaLinux:10 | Package registry (OSV) |
| almalinux:kernel-64k-debug-core | 6.12.0-211.49.1.el10_2 · AlmaLinux:10 | Package registry (OSV) |
| almalinux:kernel-64k-debug-devel | 6.12.0-211.49.1.el10_2 · AlmaLinux:10 | Package registry (OSV) |
| almalinux:kernel-64k-debug-devel-matched | 6.12.0-211.49.1.el10_2 · AlmaLinux:10 | Package registry (OSV) |
| almalinux:kernel-64k-debug-modules | 6.12.0-211.49.1.el10_2 · AlmaLinux:10 | Package registry (OSV) |
| almalinux:kernel-64k-debug-modules-core | 6.12.0-211.49.1.el10_2 · AlmaLinux:10 | Package registry (OSV) |
| almalinux:kernel-64k-debug-modules-extra | 6.12.0-211.49.1.el10_2 · AlmaLinux:10 | Package registry (OSV) |
| almalinux:kernel-64k-devel | 6.12.0-211.49.1.el10_2 · AlmaLinux:10 | Package registry (OSV) |
| almalinux:kernel-64k-devel-matched | 6.12.0-211.49.1.el10_2 · AlmaLinux:10 | Package registry (OSV) |
| debian:linux | 6.1.180-1 · Debian:12 | Package registry (OSV) |
| debian:linux-6.12 | 6.12.100-1~deb12u1 · Debian:12 | Package registry (OSV) |
| red hat:kernel-64k-debug-debuginfo | 0:6.12.0-211.49.1.el10_2 · Red Hat:enterprise_linux:10.2 | Package registry (OSV) |
| red hat:kernel-64k-debug-devel | 0:6.12.0-211.49.1.el10_2 · Red Hat:enterprise_linux:10.2 | Package registry (OSV) |
| red hat:kernel-64k-debug-devel-matched | 0:6.12.0-211.49.1.el10_2 · Red Hat:enterprise_linux:10.2 | Package registry (OSV) |
| red hat:kernel-64k-debuginfo | 0:6.12.0-211.49.1.el10_2 · Red Hat:enterprise_linux:10.2 | Package registry (OSV) |
| red hat:kernel-64k-devel | 0:6.12.0-211.49.1.el10_2 · Red Hat:enterprise_linux:10.2 | Package registry (OSV) |
| red hat:kernel-64k-devel-matched | 0:6.12.0-211.49.1.el10_2 · Red Hat:enterprise_linux:10.2 | Package registry (OSV) |
| red hat:kernel-debug-debuginfo | 0:6.12.0-211.49.1.el10_2 · Red Hat:enterprise_linux:10.2 | Package registry (OSV) |
+11
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.
- CVE-2026-640376 days apartwifi: iwlwifi: mld: fix TSO segmentation explosion when AMSDU is disabled39Monitor
- CVE-2026-640466 days apartnet: tls: prevent chain-after-chain in plain text SG39Monitor
- CVE-2026-5322130 days apartip6_vti: fix incorrect tunnel matching in vti6_tnl_lookup()39Monitor
- CVE-2026-4611558 days apartblock: add pgmap check to biovec_phys_mergeable39Monitor
- CVE-2026-4311480 days apartnetfilter: nft_set_pipapo_avx2: don't return non-matching entry on expiry37Monitor
- CVE-2026-641066 days apartKVM: arm64: vgic-its: Reject restored DTE with out-of-range num_eventid_bits36Monitor
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
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- A user must open a link or visit a page.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- low · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- Low
- Availability impact
- High
Weakness class (CWE)
CWE-20 · Improper Input ValidationCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Buffer Overflow via Environment VariablesCAPEC-10likelihood: High · High
- Server Side Include (SSI) InjectionCAPEC-101likelihood: High · High
- Cross Zone ScriptingCAPEC-104likelihood: Medium · High
- Command Line Execution through SQL InjectionCAPEC-108likelihood: Low · Very High
- Object Relational Mapping InjectionCAPEC-109likelihood: Low · High
- SQL Injection through SOAP Parameter TamperingCAPEC-110likelihood: High · Very High
- Double EncodingCAPEC-120likelihood: Low · Medium
- Subverting Environment Variable ValuesCAPEC-13likelihood: High · Very High
ATT&CK techniques
- Obfuscated Files or InformationT1027
- Masquerading: Invalid Code SignatureT1036.001
- Steal Web Session CookieT1539
- Subvert Trust Controls: Code SigningT1553.002
- Impair Defenses:Impair Command History LoggingT1562.003
- Hijack Execution Flow:Dynamic Linker HijackingT1574.006
- Hijack Execution Flow:Path Interception by PATH Environment VariableT1574.007
Change log
- SSVC exploitation— → none
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (7 more)Show less
- git.kernel.org/stable/c/5f6f2241034f189c69d4d0b5f8fe24a0c25b0c14
- git.kernel.org/stable/c/b84e002e0df26bbc6cbd3ca01b8212601fe0ae7d
- git.kernel.org/stable/c/c6c484a7d5bff6b929a86d7ed5130f29834c6a0d
- git.kernel.org/stable/c/e3d9c7160d483fc8f9e225aafad8ecbbc43f3151
- git.kernel.org/stable/c/ee2216dbdf0c677e89bb43e03247dba590ed00ef
- git.kernel.org/stable/c/f511807feee7cb29b61bdfa86472c7e9e2e5df94
- git.kernel.org/stable/c/f80add1bfb3425100a325b14f19648e75669a954
Vendor advisories and official records. Exploit/PoC links are deliberately left out.