HOL LogoGuard

Explore HOL

  • HOL home
  • AI agent registry
  • AI plugins
  • Open standards
  • HOL members
  • Sponsor HOL
  • Advertise with HOL

Guard product

  • Guard overviewLocal security and control for AI agents and the tools they use.
  • FeaturesRuntime protection, policy routing, review, and evidence.

Explore Guard

  • Product previewWalk through Guard surfaces in read-only demo mode.
  • ComparisonCompare Guard with native controls and AI security vendors.

AI tools

  • All AI toolsEvery supported AI tool and how Guard applies policy to it.
  • Codex
  • Claude Code
  • Cursor
  • Antigravity CLI
  • OpenCode
  • Hermes
  • OpenClaw
  • GitHub Copilot CLI
  • Antigravity
  • Kimi
  • Grok
  • Pi / Oh My Pi
  • Zcode

Extensions

  • All extensionsBrowse command and MCP coverage with owners and stated limits.
  • Command coverageShell command protection across clouds, databases, backups, and packages.
  • MCP server coverageSee how Guard maps risk state across MCP tools and servers.
  • Core safetyThe safety floor listings that ship with Guard.
  • Data and resilienceBackup and storage command protection.
  • Cloud and infrastructureAWS, Azure, GCP, Kubernetes, and more.

Security

  • AI security hubSecurity research, advisories, and agent safety coverage.
  • AI tool securitySecurity profiles for each supported coding agent.
  • Safe labsHands-on attack simulations with safe boundaries.
  • Redacted warningsReal blocked actions with sensitive details removed.
  • AdvisoriesCoordinated disclosure reports for AI tooling.
  • Active CVEsSearch active CVEs affecting AI tooling.

Learn

  • Security guidesPractical guides for securing AI agent workflows.
  • DocsInstall, configure, and operate Guard with confidence.
  • ResearchPublished security research, benchmarks, and methodology.

Community

  • ReleasesVersion history, shipped changes and upgrade notes.
  • ContributorsThe people and contributions behind HOL Guard.
  • AffiliatesShare Guard with your audience and earn from referrals.
  • SponsorFund agreed research, implementation and shared testing through the HOL Partner Program.
  • AdvertiseCompare README logo placements, previews and monthly prices, or promote a plugin or extension.
PricingEnterpriseOpen AppInstall Guard
  1. Guard
  2. Security
  3. CVEs
  4. CVE 2026 64388 smbclient fix chownchgrp with smb3 posix
HOL Guard

Public security guidance for teams protecting AI harnesses, MCP servers, skills, prompts, and local tool execution.

Install Guard

AI Security

  • Prompt injection
  • MCP security
  • OWASP MCP mapping
  • Supply chain

Resources

  • Trust packet
  • Harness setup
  • Redacted warnings
  • Safe labs

Product

  • Install Guard
  • Pricing
  • Open dashboard
Guard
  • Guard Overview
  • Releases
  • Contributors
  • Install Guard
  • Pricing
Docs
  • Documentation Index
  • Developer Hub
  • API Reference
  • Root OpenAPI
  • Registry OpenAPI
  • Run in Postman
  • Standards
  • Submit ERC-8004 Contract
  • Feature Your Agent
Best Plugins
  • Browse Plugins
  • Plugin Launches
  • Best Claude Plugins
  • Best Codex Plugins
  • Best Grok Plugins
  • Best Kimi Plugins
  • Best DeepSeek Plugins
  • Best Antigravity Plugins
  • Best MCP Servers
  • Best Cursor Plugins
  • Best OpenCode Plugins
Best Agents
  • Best ERC-8004 Agents
  • Best Virtuals Agents
  • Best MCP Servers
  • Best A2A Agents
  • Best x402 Payable
  • All Categories
Community
  • Contribute to HOL
  • Telegram
  • X
More
  • About HOL
  • Sponsor
  • Advertise
  • Affiliate program
  • Contact
  • Blog
  • GitHub
  • Privacy
  • Terms of Service
Settings

Copyright © 2026 HOL DAO LLC. All rights reserved.

Back to active CVEs
High · CVSS 7.8CVE-2026-64388

smb/client: fix chown/chgrp with SMB3 POSIX ExtensionsCVE-2026-64388

Answer in brief

CVE-2026-64388 records a High severity (CVSS 7.8) vulnerability in smb/client: fix chown/chgrp with SMB3 POSIX Extensions. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Jul 25, 2026Updated Oct 30, 2026Source checked Nov 5, 2026First seen by HOL Aug 5, 2026Material review Oct 30, 2026
Upstream Advisory

Record context

Vulnerability class
Vulnerability
EPSS
Not reported
CWE IDs
NVD-CWE-noinfo, CWE-682
Source
CVE List V5
Source checked
Nov 5, 2026
References
6 linked sources
Open source record

Key facts

Risk
High · CVSS 7.8
Exploitation
Not marked as known exploited
Affected software
6 mapped packages or products
Fix availability
Available

Why this deserves its current priority

CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.

Affected products and reported versions
ProductAffected versionsFixed versions
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*Not reportedNot reported
Mapped affected packages and fixed versions
PackageAffected rangeFixed version
Linux/Linuxgeneric>=b326614ea2159ea5c835d320f261d05d080cd201 <550cfb8a81181331d4d0f76ab75ee58a0bf41e3e || >=b326614ea2159ea5c835d320f261d05d080cd201 <760ef2c579c2609cf17fb1cd5392f64d42d43d33550cfb8a81181331d4d0f76ab75ee58a0bf41e3e, 760ef2c579c2609cf17fb1cd5392f64d42d43d33
Linux/Linuxgeneric4.18Not reported
Linux/Linuxgeneric>=b326614ea2159ea5c835d320f261d05d080cd201 <3eaec47518e126e6dcd1a48521d740278073f0ec || >=b326614ea2159ea5c835d320f261d05d080cd201 <550cfb8a81181331d4d0f76ab75ee58a0bf41e3e || >=b326614ea2159ea5c835d320f261d05d080cd201 <760ef2c579c2609cf17fb1cd5392f64d42d43d333eaec47518e126e6dcd1a48521d740278073f0ec, 550cfb8a81181331d4d0f76ab75ee58a0bf41e3e, 760ef2c579c2609cf17fb1cd5392f64d42d43d33
Linux/Linuxgeneric>=b326614ea2159ea5c835d320f261d05d080cd201 <6825a45f6b8ef76b0ee32649ec3d6e39ca143a18 || >=b326614ea2159ea5c835d320f261d05d080cd201 <27ead8c5418af6bfab711079fecb9414d78d4cae || >=b326614ea2159ea5c835d320f261d05d080cd201 <3eaec47518e126e6dcd1a48521d740278073f0ec || >=b326614ea2159ea5c835d320f261d05d080cd201 <550cfb8a81181331d4d0f76ab75ee58a0bf41e3e || >=b326614ea2159ea5c835d320f261d05d080cd201 <760ef2c579c2609cf17fb1cd5392f64d42d43d336825a45f6b8ef76b0ee32649ec3d6e39ca143a18, 27ead8c5418af6bfab711079fecb9414d78d4cae, 3eaec47518e126e6dcd1a48521d740278073f0ec, 550cfb8a81181331d4d0f76ab75ee58a0bf41e3e, 760ef2c579c2609cf17fb1cd5392f64d42d43d33
Linux/Linuxgeneric>=b326614ea2159ea5c835d320f261d05d080cd201 <c0fe1118a1471d459f76c3e70ff2abbf784ce6bf || >=b326614ea2159ea5c835d320f261d05d080cd201 <6825a45f6b8ef76b0ee32649ec3d6e39ca143a18 || >=b326614ea2159ea5c835d320f261d05d080cd201 <27ead8c5418af6bfab711079fecb9414d78d4cae || >=b326614ea2159ea5c835d320f261d05d080cd201 <3eaec47518e126e6dcd1a48521d740278073f0ec || >=b326614ea2159ea5c835d320f261d05d080cd201 <550cfb8a81181331d4d0f76ab75ee58a0bf41e3e || >=b326614ea2159ea5c835d320f261d05d080cd201 <760ef2c579c2609cf17fb1cd5392f64d42d43d33c0fe1118a1471d459f76c3e70ff2abbf784ce6bf, 6825a45f6b8ef76b0ee32649ec3d6e39ca143a18, 27ead8c5418af6bfab711079fecb9414d78d4cae, 3eaec47518e126e6dcd1a48521d740278073f0ec, 550cfb8a81181331d4d0f76ab75ee58a0bf41e3e, 760ef2c579c2609cf17fb1cd5392f64d42d43d33

Recommended response

  1. 1Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux, Linux/Linux.
  2. 2Review the reported fix. Update Linux/Linux to 550cfb8a81181331d4d0f76ab75ee58a0bf41e3e; Linux/Linux to 3eaec47518e126e6dcd1a48521d740278073f0ec; Linux/Linux to 6825a45f6b8ef76b0ee32649ec3d6e39ca143a18; Linux/Linux to c0fe1118a1471d459f76c3e70ff2abbf784ce6bf if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

  1. Published upstream

    Jul 25, 2026

    Evidence: source:cvelist:source_dates:source-dates:record

  2. Source modified

    Oct 30, 2026

    Evidence: source:cvelist:source_dates:source-dates:record

  3. First seen by HOL

    Aug 5, 2026

Sources and claim methodology

  • Source referencegit.kernel.org
  • Source referencegit.kernel.org
  • Source referencegit.kernel.org
  • Source referencegit.kernel.org
  • Source referencegit.kernel.org
  • Source referencegit.kernel.org
Upstream source description

In the Linux kernel, the following vulnerability has been resolved: smb/client: fix chown/chgrp with SMB3 POSIX Extensions Ownership (chown) and group (chgrp) modifications were being ignored when mounting with SMB3 POSIX Extensions unless CIFS_MOUNT_CIFS_ACL or CIFS_MOUNT_MODE_FROM_SID were also explicitly set. Fix this by checking for posix_extensions in cifs_setattr_nounix() when updating UID and GID, ensuring that id_mode_to_cifs_acl() is called to map and set the ownership/group information on the server.

Quoted source text, attributed separately from HOL analysis.