CVE-2026-46195: Linux Kernel buffer overflow (CVSS 9.8)

Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: validate dacloffset before building DACL pointers parse_sec_desc(), build_sec_desc(), and the chown path in id_mode_to_cifs_acl() all add the server-supplied dacloffset to pntsd before proving a DACL header fits inside the returned security descriptor. On 32-bit builds a malicious server can return dacloffset near U32_MAX, wrap the derived DACL pointer below end_of_acl, and then slip past the later pointer-based bounds checks. build_sec_desc() and id_mode_to_cifs_acl() can then dereference DACL fields from the wrapped pointer in the chmod/chown rewrite paths. Validate dacloffset numerically before building any DACL pointer and reuse the same helper at the three DACL entry points.

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

ScopeUnchanged

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Affected products

Linux Kernel≥ 5.12 < 6.6.140 · ≥ 6.13 < 6.18.30 · ≥ 6.19 < 7.0.7 · ≥ 6.7 < 6.12.88

Remediation

Fixed in

Linux Kernel≥ 6.6.140

Patch & vendor advisories

References

and 3 more references

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2026-46195 being actively exploited?

CVE-2026-46195 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.68%.

How severe is CVE-2026-46195?

CVE-2026-46195 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 0.68% probability of exploitation.

Which products are affected by CVE-2026-46195?

Affected products include Linux Kernel.

How do I fix CVE-2026-46195?

Upgrade affected software to a fixed version, for example Linux Kernel 6.6.140 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-46195 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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