widely-deployed-product-advisorycloud-service-vulnerabilityprivilege-escalation-method

Docker Sandboxes TOCTOU Flaw Lets Guests Redirect Host Unix-Socket Connections

Patch & Detection Intelligence · 12 sources · Updated 2mo ago · First seen Sep 17, 2026

Docker disclosed and fixed CVE-2026-79994, a high-severity time-of-check to time-of-use (TOCTOU) vulnerability in the host-side relay used by Docker Sandboxes. A malicious sandbox guest could alter an intermediate workspace directory after validation of a Unix-socket path, replacing it with a symbolic link and causing the trusted relay to connect to an AF_UNIX socket outside the approved workspace.

The flaw affects Docker Sandboxes versions 0.37.0 through versions before 0.41.0; version 0.41.0 includes the specific fix. Docker's broader security advisory recommends upgrading deployments to 0.43.0 or later. Although the issue does not directly grant unrestricted host filesystem access, it can enable a guest to influence connections to reachable host socket services, potentially affecting confidentiality and integrity; no active exploitation has been confirmed.

Patch this, or something else?See real exploitation activity before you spend the cycle.

Triage this advisory

Event timeline

How this story unfolded

Events from the most recent confirmed update back to the earliest known activity.

7 events · Sep 7, 2026 – Sep 15, 2026

Reported Sep 17, 20262mo ago
Docker updates address three Sandboxes vulnerabilities
Docker released Docker Sandboxes security updates addressing three vulnerabilities—two rated critical and one high severity—that could enable arbitrary file read/write and arbitrary code execution. Versions 0.28.0 through those before 0.42.0 are affected, and users were advised to update.
Risolte vulnerabilità in Docker - ACN
Reported Sep 17, 20262mo ago
Docker fixes CVE-2026-17106 destination-escape flaw
Docker fixed CVE-2026-17106, a destination-escape vulnerability affecting the `docker container cp` command, in Docker Desktop 4.86.0.
Critical Docker Sandbox Vulnerabilities Enable Malicious Guests to Escape Isolated microVM Workspaces | Cryptika Cybersecurity
Reported Sep 17, 20262mo ago
Docker fixes CVE-2026-79994 Unix-socket relay flaw
Docker fixed high-severity CVE-2026-79994 in the Docker Sandboxes host-side relay. The TOCTOU flaw affected versions 0.37.0 through versions before 0.41.0 and could let a malicious guest redirect the relay to an arbitrary reachable pathname-based Unix socket; version 0.41.0 contains the fix, and no active exploitation was confirmed.
Docker Sandboxes High Risk Unix Socket Exploit CVE-2026-79994
Sep 15, 20262mo ago
Tenable lists Ubuntu docker.io-app as unpatched for CVE-2026-79994
A Tenable Nessus Unix agent plugin identified Canonical Ubuntu LTS releases 16.04 through 26.04 and the Ubuntu docker.io-app package as affected by and unpatched for CVE-2026-79994. The plugin characterized the issue as locally exploitable with high integrity impact and reported no known exploits.
Linux Distros Unpatched Vulnerability : CVE-2026-79994 | Tenable®
Sep 15, 20262mo ago
Docker corrects CVE-2026-79994 fixed-version information
Docker corrected its advisory after initially listing Docker Sandboxes 0.41.0 as the first release fixing CVE-2026-79994. The company clarified that version 0.42.0 is the first fixed release for the Unix-domain-socket relay flaw.
Critical Docker Sandboxes Flaw Lets Malicious Guest Code Read and Modify macOS Host Files
Sep 15, 20262mo ago
Docker publishes Docker Sandboxes security advisory
Docker published a security advisory concerning vulnerabilities affecting Docker Sandboxes releases earlier than version 0.43.0. The advisory recommended upgrading affected deployments, without providing CVE identifiers, severity ratings, technical details, or evidence of exploitation.
CIRT.GY | Docker Security Advisory (September 17th, 2026)
Sep 7, 20262mo ago
Docker releases 0.42.0 to fix CVE-2026-77179 and CVE-2026-79994
Docker released Docker Sandboxes 0.42.0 to remediate critical CVE-2026-77179, a macOS virtio-fs symlink race that could let a guest read or modify host files available to the VMM user, and high-severity CVE-2026-79994, a Unix-socket relay TOCTOU flaw. Docker advised upgrading immediately and, where that was not possible, using clone mode and avoiding read-write host mounts.
Critical Docker Sandbox Vulnerabilities Enable Malicious Guests to Escape Isolated microVM Workspaces

Linked entities

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Vulnerabilities, threat actors, malware, products, organizations, and breaches Mallory has linked to this story.

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Vulnerabilities

1 linked

TOCTOU Symlink Race in Docker Sandboxes Unix-Socket Relay (CVE-2026-79994)

Affected products

1 linked

Docker Sandboxes

Do you run this?See real exploitation activity behind this advisory so you can triage it against everything else in the queue.

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Source coverage

Sources

12 references tracked. Mallory keeps watching after this page renders.

Cysecurity NewsNews · Sep 18, 2026

Docker Fixes Critical Sandboxes Flaw That Could Expose Host Files - CySecurity News - Latest Information Security and Hacking IncidentsOpen source ↗

Mkd CirtNews · Sep 18, 2026

Критичен пропуст во Docker Sandboxes им овозможува на малициозен код од guest системот да чита и менува датотеки на macOS host системот | MKD-CIRT | Национален центар за одговор на компјутерски инцидентиOpen source ↗

ThecybersecguruNews · Sep 18, 2026

Critical Docker Sandboxes Flaws CVE-2026-77179 & CVE-2026-79994 Enable AI Agent Host Escape | The CyberSec GuruOpen source ↗

The Hacker NewsNews · Sep 17, 2026

Critical Docker Sandboxes Flaw Lets Malicious Guest Code Read and Modify macOS Host FilesOpen source ↗

4 additional sources from 17-09-2026 to 17-09-2026

LinuxsecurityNews · Sep 17, 2026

Docker Sandboxes High Risk Unix Socket Exploit CVE-2026-79994Open source ↗

Cirt GyNews · Sep 17, 2026

CIRT.GY | Docker Security Advisory (September 17th, 2026)Open source ↗

Tenable Nessus PluginsNews · Sep 17, 2026

Linux Distros Unpatched Vulnerability : CVE-2026-79994 | Tenable®Open source ↗

Docker-Security-AnnouncementsNews

Docker-Security-AnnouncementsOpen source ↗

Mallory platform

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widely-deployed-product-advisorycloud-service-vulnerabilityprivilege-escalation-method

Docker Sandboxes TOCTOU Flaw Lets Guests Redirect Host Unix-Socket Connections

Patch & Detection Intelligence · 12 sources · Updated 2mo ago · First seen Sep 17, 2026

Patch this, or something else?See real exploitation activity before you spend the cycle.

Triage this advisory

Event timeline

How this story unfolded

Events from the most recent confirmed update back to the earliest known activity.

7 events · Sep 7, 2026 – Sep 15, 2026

Reported Sep 17, 20262mo ago
Docker updates address three Sandboxes vulnerabilities
Docker released Docker Sandboxes security updates addressing three vulnerabilities—two rated critical and one high severity—that could enable arbitrary file read/write and arbitrary code execution. Versions 0.28.0 through those before 0.42.0 are affected, and users were advised to update.
Risolte vulnerabilità in Docker - ACN
Reported Sep 17, 20262mo ago
Docker fixes CVE-2026-17106 destination-escape flaw
Docker fixed CVE-2026-17106, a destination-escape vulnerability affecting the `docker container cp` command, in Docker Desktop 4.86.0.
Critical Docker Sandbox Vulnerabilities Enable Malicious Guests to Escape Isolated microVM Workspaces | Cryptika Cybersecurity
Reported Sep 17, 20262mo ago
Docker fixes CVE-2026-79994 Unix-socket relay flaw
Docker fixed high-severity CVE-2026-79994 in the Docker Sandboxes host-side relay. The TOCTOU flaw affected versions 0.37.0 through versions before 0.41.0 and could let a malicious guest redirect the relay to an arbitrary reachable pathname-based Unix socket; version 0.41.0 contains the fix, and no active exploitation was confirmed.
Docker Sandboxes High Risk Unix Socket Exploit CVE-2026-79994
Sep 15, 20262mo ago
Tenable lists Ubuntu docker.io-app as unpatched for CVE-2026-79994
A Tenable Nessus Unix agent plugin identified Canonical Ubuntu LTS releases 16.04 through 26.04 and the Ubuntu docker.io-app package as affected by and unpatched for CVE-2026-79994. The plugin characterized the issue as locally exploitable with high integrity impact and reported no known exploits.
Linux Distros Unpatched Vulnerability : CVE-2026-79994 | Tenable®
Sep 15, 20262mo ago
Docker corrects CVE-2026-79994 fixed-version information
Docker corrected its advisory after initially listing Docker Sandboxes 0.41.0 as the first release fixing CVE-2026-79994. The company clarified that version 0.42.0 is the first fixed release for the Unix-domain-socket relay flaw.
Critical Docker Sandboxes Flaw Lets Malicious Guest Code Read and Modify macOS Host Files
Sep 15, 20262mo ago
Docker publishes Docker Sandboxes security advisory
Docker published a security advisory concerning vulnerabilities affecting Docker Sandboxes releases earlier than version 0.43.0. The advisory recommended upgrading affected deployments, without providing CVE identifiers, severity ratings, technical details, or evidence of exploitation.
CIRT.GY | Docker Security Advisory (September 17th, 2026)
Sep 7, 20262mo ago
Docker releases 0.42.0 to fix CVE-2026-77179 and CVE-2026-79994
Docker released Docker Sandboxes 0.42.0 to remediate critical CVE-2026-77179, a macOS virtio-fs symlink race that could let a guest read or modify host files available to the VMM user, and high-severity CVE-2026-79994, a Unix-socket relay TOCTOU flaw. Docker advised upgrading immediately and, where that was not possible, using clone mode and avoiding read-write host mounts.
Critical Docker Sandbox Vulnerabilities Enable Malicious Guests to Escape Isolated microVM Workspaces

Linked entities

Related entities

Vulnerabilities, threat actors, malware, products, organizations, and breaches Mallory has linked to this story.

Open in app →

Vulnerabilities

1 linked

TOCTOU Symlink Race in Docker Sandboxes Unix-Socket Relay (CVE-2026-79994)

Affected products

1 linked

Docker Sandboxes

Do you run this?See real exploitation activity behind this advisory so you can triage it against everything else in the queue.

Prioritize This Patch

Source coverage

Sources

12 references tracked. Mallory keeps watching after this page renders.

Cysecurity NewsNews · Sep 18, 2026

Docker Fixes Critical Sandboxes Flaw That Could Expose Host Files - CySecurity News - Latest Information Security and Hacking IncidentsOpen source ↗

Mkd CirtNews · Sep 18, 2026

ThecybersecguruNews · Sep 18, 2026

Critical Docker Sandboxes Flaws CVE-2026-77179 & CVE-2026-79994 Enable AI Agent Host Escape | The CyberSec GuruOpen source ↗

The Hacker NewsNews · Sep 17, 2026

Critical Docker Sandboxes Flaw Lets Malicious Guest Code Read and Modify macOS Host FilesOpen source ↗

4 additional sources from 17-09-2026 to 17-09-2026

LinuxsecurityNews · Sep 17, 2026

Docker Sandboxes High Risk Unix Socket Exploit CVE-2026-79994Open source ↗

Cirt GyNews · Sep 17, 2026

CIRT.GY | Docker Security Advisory (September 17th, 2026)Open source ↗

Tenable Nessus PluginsNews · Sep 17, 2026

Linux Distros Unpatched Vulnerability : CVE-2026-79994 | Tenable®Open source ↗

Docker-Security-AnnouncementsNews

Docker-Security-AnnouncementsOpen source ↗

Mallory platform

See the full picture, correlated to your attack surface.

This page covers what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which threat actors are using it right now, and what to deploy next.

Start Free Trial Open in App

Exposure mappingMap indicators from this story to your assets and identify affected systems in minutes.

Threat actor evidenceEvery observed campaign, victim, and pivot linked to actors named in this story.

Associated malwareMalware, exploits, and IOCs connected to the activity described here.

Detection signaturesYARA, Sigma, and Snort rules deployed to your SIEM as soon as they’re published.

Scheduled alertsGet matching new stories delivered to your team as they break, not the next morning.

AI threadsAsk questions about this story and take action on the answers.

Docker Sandboxes TOCTOU Flaw Lets Guests Redirect Host Unix-Socket Connections

How this story unfolded

Docker updates address three Sandboxes vulnerabilities

Docker fixes CVE-2026-17106 destination-escape flaw

Docker fixes CVE-2026-79994 Unix-socket relay flaw

Tenable lists Ubuntu docker.io-app as unpatched for CVE-2026-79994

Docker corrects CVE-2026-79994 fixed-version information

Docker publishes Docker Sandboxes security advisory

Docker releases 0.42.0 to fix CVE-2026-77179 and CVE-2026-79994

Related entities

Vulnerabilities

Affected products

Sources

See the full picture, correlated to your attack surface.

Related stories

Docker Sandboxes Read-Only Mount Bypass Let Sandbox Code Modify Host Files

Public Exploit Enables Host-Root Escape From Unpatched Ubuntu Containers

docker-socket-proxy Flaw Exposes Container Filesystems via `CONTAINERS=1`

Docker Sandboxes TOCTOU Flaw Lets Guests Redirect Host Unix-Socket Connections

How this story unfolded

Docker updates address three Sandboxes vulnerabilities

Docker fixes CVE-2026-17106 destination-escape flaw

Docker fixes CVE-2026-79994 Unix-socket relay flaw

Tenable lists Ubuntu docker.io-app as unpatched for CVE-2026-79994

Docker corrects CVE-2026-79994 fixed-version information

Docker publishes Docker Sandboxes security advisory

Docker releases 0.42.0 to fix CVE-2026-77179 and CVE-2026-79994

Related entities

Vulnerabilities

Affected products

Sources

See the full picture, correlated to your attack surface.

Related stories

Docker Sandboxes Read-Only Mount Bypass Let Sandbox Code Modify Host Files

Public Exploit Enables Host-Root Escape From Unpatched Ubuntu Containers

docker-socket-proxy Flaw Exposes Container Filesystems via `CONTAINERS=1`