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Linux Kernel EUVDEUVD-2026-55444

| CVE-2026-68343 CRITICAL
2026-08-10 Linux GHSA-jv66-q3cr-4688
Information Disclosure Linux
Critical
Disputed · 9.1 Vendor: Linux
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Severity by source

Sources disagree (Medium–Critical)
Vendor (Linux) PRIMARY
9.1 CRITICAL
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
vuln.today AI
6.8 MEDIUM

Attacker must control the SMB server and the client must mount/traverse a DFS share, so AC:H and UI:R; OOB read yields C:H and A:H (crash) with no integrity impact.

3.1 AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:H
4.0 AV:N/AC:H/AT:P/PR:N/UI:P/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N
SUSE
5.5 MEDIUM
AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Red Hat
7.0 MEDIUM
qualitative

vuln.today treats the vendor’s rating as authoritative. A higher third-party CVSS (e.g. CISA-ADP) is shown for transparency but does not drive the headline severity.

CVSS VectorVendor: Linux

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
High

Lifecycle Timeline

5
Analysis Generated
Aug 14, 2026 - 03:03 vuln.today
CVSS changed
Aug 13, 2026 - 23:37 NVD
9.1 (CRITICAL)
Patch available
Aug 10, 2026 - 14:18 EUVD
CVE Published
Aug 10, 2026 - 12:03 cve.org
CRITICAL 9.1
CVE Published
Aug 10, 2026 - 12:03 cve.org
UNKNOWN (no severity yet)

DescriptionCVE.org

In the Linux kernel, the following vulnerability has been resolved:

smb: client: validate DFS referral PathConsumed

parse_dfs_referrals() validates that the response contains the fixed referral entry array and, on for-next, the per-referral string offsets. However, the response also contains a PathConsumed value that is later used for DFS path parsing.

If a malformed response provides a PathConsumed value larger than the search name, later DFS parsing can advance beyond the end of the path.

Validate PathConsumed against the search name length before storing it in the parsed referral.

AnalysisAI

Out-of-bounds read in the Linux kernel's SMB/CIFS client DFS referral parser (parse_dfs_referrals) affects systems that mount SMB shares using DFS. A malicious or compromised SMB server can return a referral response whose PathConsumed value exceeds the search name length, causing later DFS path parsing to advance past the end of the buffer and leak adjacent kernel memory or crash the client. Tagged as Information Disclosure with a 9.1 CVSS; EPSS is low (0.18%, 7th percentile) and there is no public exploit identified at time of analysis.

Technical ContextAI

The affected code is the in-kernel SMB client (fs/smb/client, formerly cifs), specifically parse_dfs_referrals(), which decodes Distributed File System (DFS) referral responses used to redirect clients to the correct file server for a namespace path. The existing code validates the fixed referral entry array and the per-referral string offsets, but does not validate the response's PathConsumed field, which reports how many bytes of the requested path the server 'consumed.' That value is later trusted during DFS path parsing to advance a pointer within the search name. The root-cause class is an out-of-bounds read (CWE-125): an untrusted length from a network peer is used as an offset without bounds-checking it against the actual search name length. CPE data identifies the product only generically as cpe:2.3:a:linux:linux, i.e. the mainline Linux kernel; the flaw is present wherever the CIFS/SMB client with DFS support is compiled and used.

RemediationAI

Vendor-released patch: update to a fixed stable kernel - 6.6.148, 6.12.101, 6.18.42, 7.1.6, or 7.2-rc5 (or later in each series) - or apply your distribution's backport of commits 5b439f39f33e / 285bd4a5f3f1 / 2fdd6d196c65 / 9f88a99ed511 / f6f5ee2aa33b from git.kernel.org/stable. Verify patch level via https://nvd.nist.gov/vuln/detail/CVE-2026-68343 and the linked kernel.org commits. As compensating controls where patching is delayed: avoid mounting SMB/CIFS shares from untrusted or internet-facing servers, disable DFS traversal / avoid DFS-backed mounts where feasible, unload or blacklist the cifs kernel module on hosts that do not need SMB client functionality (side effect: no SMB share mounting), and enforce SMB signing plus network segmentation to reduce the risk of a MITM injecting malicious referral responses (side effect: signing adds CPU overhead and requires server support).

Same technique Information Disclosure

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Vendor StatusVendor

SUSE

Severity: Moderate
Product Status
SUSE Linux Enterprise Desktop 15 SP7 Affected
SUSE Linux Enterprise Desktop 15 SP7 Affected
SUSE Linux Enterprise High Availability Extension 15 SP7 Affected
SUSE Linux Enterprise High Availability Extension 15 SP7 Affected
SUSE Linux Enterprise High Availability Extension 16.0 Affected

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EUVD-2026-55444 vulnerability details – vuln.today
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