CopyEscape: Container-to-host arbitrary file write via docker cp (CVE-2026-17106)
CVE-2026-17106, known as CopyEscape, is a high-severity vulnerability in Docker's 'docker cp' command that allows a malicious container to write arbitrary files to the host filesystem. The flaw stems from a filesystem race condition during archive creation combined with unsafe symbolic link handling during extraction. This can lead to arbitrary file creation or overwriting on the host and potentially code execution depending on the privileges of the Docker CLI user. Docker has released official fixes in Docker Engine/CLI version 29.7.2 and later, Docker Desktop 4.86.0 and later, and Docker Sandboxes 0.38.0 and later.
AI Analysis
Technical Summary
CopyEscape (CVE-2026-17106) is a vulnerability in Docker's 'docker cp' command caused by a race condition during archive creation and unsafe symbolic link handling during extraction. This allows a malicious container to write or overwrite arbitrary files on the host filesystem. The impact can escalate to code execution depending on the privileges of the user running the Docker CLI. Docker confirmed that the sandbox copy command (sbx cp) was also affected. Official patches addressing this vulnerability were released in Docker Engine/CLI 29.7.2+, Docker Desktop 4.86.0+, and Docker Sandboxes 0.38.0+.
Potential Impact
The vulnerability enables a malicious container to write arbitrary files to the host filesystem, which can lead to file creation or overwriting on the host. Depending on the privileges of the Docker CLI user, this may result in code execution on the host system. This poses a significant risk to host integrity and security.
Mitigation Recommendations
Docker has released official fixes for this vulnerability in Docker Engine/CLI version 29.7.2 and later, Docker Desktop 4.86.0 and later, and Docker Sandboxes 0.38.0 and later. Users should upgrade to these versions or later to mitigate the risk. No additional vendor advisories indicate other mitigation steps or that no action is required.
CopyEscape: Container-to-host arbitrary file write via docker cp (CVE-2026-17106)
Description
CVE-2026-17106, known as CopyEscape, is a high-severity vulnerability in Docker's 'docker cp' command that allows a malicious container to write arbitrary files to the host filesystem. The flaw stems from a filesystem race condition during archive creation combined with unsafe symbolic link handling during extraction. This can lead to arbitrary file creation or overwriting on the host and potentially code execution depending on the privileges of the Docker CLI user. Docker has released official fixes in Docker Engine/CLI version 29.7.2 and later, Docker Desktop 4.86.0 and later, and Docker Sandboxes 0.38.0 and later.
Reddit Discussion
https://www.imperva.com/blog/copyescape-taking-over-docker-hosts-with-docker-cp/
Author here. I discovered a vulnerability in docker cp that allows a malicious container to create or overwrite files on the machine running the Docker CLI.
The exploit combines a filesystem race in Docker’s archive creation with unsafe symlink handling during extraction. Depending on the CLI user’s privileges, this can lead to code execution. Docker confirmed that sbx cp was also affected.
Fixed versions:
- Docker Engine/CLI 29.7.2+
- Docker Desktop 4.86.0+
- Docker Sandboxes 0.38.0+
Happy to answer technical questions.
Links cited in this discussion
Affected software
Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CopyEscape (CVE-2026-17106) is a vulnerability in Docker's 'docker cp' command caused by a race condition during archive creation and unsafe symbolic link handling during extraction. This allows a malicious container to write or overwrite arbitrary files on the host filesystem. The impact can escalate to code execution depending on the privileges of the user running the Docker CLI. Docker confirmed that the sandbox copy command (sbx cp) was also affected. Official patches addressing this vulnerability were released in Docker Engine/CLI 29.7.2+, Docker Desktop 4.86.0+, and Docker Sandboxes 0.38.0+.
Potential Impact
The vulnerability enables a malicious container to write arbitrary files to the host filesystem, which can lead to file creation or overwriting on the host. Depending on the privileges of the Docker CLI user, this may result in code execution on the host system. This poses a significant risk to host integrity and security.
Mitigation Recommendations
Docker has released official fixes for this vulnerability in Docker Engine/CLI version 29.7.2 and later, Docker Desktop 4.86.0 and later, and Docker Sandboxes 0.38.0 and later. Users should upgrade to these versions or later to mitigate the risk. No additional vendor advisories indicate other mitigation steps or that no action is required.
Technical Details
- Source Type
- Subreddit
- cybersecurity
- Reddit Score
- 0
- Discussion Level
- minimal
- Content Source
- reddit_link_post
- Post Type
- link
- Domain
- null
- Newsworthiness Assessment
- {"score":45,"reasons":["external_link","newsworthy_keywords:cve-","security_identifier","established_author","very_recent"],"isNewsworthy":true,"foundNewsworthy":["cve-"],"foundNonNewsworthy":[]}
- Has External Source
- true
- Trusted Domain
- false
Threat ID: 6a7b4614bf8831d539fda2db
Added to database: 08/11/2026, 15:56:04 UTC
Last enriched: 08/19/2026, 11:10:14 UTC
Last updated: 09/10/2026, 06:38:27 UTC
Views: 249
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.