critical CVSS 9.8

CVE-2026-56265·Docker vulnerability

Crawl4AI before 0.8.7 contains an authentication bypass vulnerability due to a hardcoded default JWT signing key in the Docker API server. Attackers who know the default key can forge valid authentication tokens for any user, bypassing authentication and gaining full access to protected functionality.

Severity
critical
Software
Docker
Fixed in
0.8.7
Published
2026-06-21

Affected versions

Until: 0.8.7

Fixed in: 0.8.7

How to fix this CVE

Upgrade Docker to version 0.8.7 or later immediately to eliminate the hardcoded JWT signing key vulnerability that allows unauthenticated token forgery. This critical flaw exposes your Docker API to complete unauthorized access without requiring valid credentials. After updating, verify that your Docker daemon is restarted to load the patched code and generate new cryptographic keys.

sudo dnf check-update docker-ce && sudo dnf update docker-ce

Defensia detects this vulnerability

What an exploitation attempt looks like

Sample log line indicative of exploitation attempts:

POST|GET|PUT|DELETE /api/v1/* with Authorization header containing JWT token, particularly repeated attempts with variations in the token payload or attempts to access /api/v1/auth or /api/v1/system endpoints from unexpected source IPs

WAF mitigation (if patching is not yet possible)

Add this rule to your WAF to block exploitation attempts while you schedule the patch. 

Block all requests to Docker API endpoints (typically TCP 2375 or 2376) from untrusted sources; implement network segmentation to restrict Docker API access to authorized management hosts only; add rate limiting to /api/v1/* endpoints to detect token forgery attempts

How to check if you are affected

  1. Check installed Docker version: docker --version | grep -oP '\d+\.\d+\.\d+'
  2. Verify the Docker API server is listening on network interfaces: sudo ss -tlnp | grep -i docker or sudo netstat -tlnp | grep -i docker
  3. Review Docker daemon logs for suspicious JWT token generation or API authentication attempts: sudo journalctl -u docker --since '24 hours ago' | grep -i 'auth\|token\|unauthorized'
  4. After patching, confirm the new version is active: docker --version and restart the Docker daemon with sudo systemctl restart docker

FAQ

What is CVE-2026-56265?

This vulnerability allows attackers to bypass Docker API authentication by leveraging a hardcoded default JWT signing key embedded in versions prior to 0.8.7, enabling them to forge valid tokens and gain unrestricted access to the entire Docker API without any valid credentials.

Is CVE-2026-56265 being actively exploited?

No, there are currently no reports of active exploitation in the wild and no public exploits are available, though the critical CVSS score of 9.8 indicates organizations should prioritize patching immediately.

What versions of Docker are affected by CVE-2026-56265?

All versions of Docker prior to 0.8.7 are affected; version 0.8.7 and later contain the fix.

How do I check if my server is vulnerable to CVE-2026-56265?

Run docker --version and extract the version number; if it is lower than 0.8.7, your installation is vulnerable. Additionally, verify that the Docker API is exposed to untrusted networks with sudo ss -tlnp | grep docker to assess risk.

Does Defensia detect CVE-2026-56265?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Docker is installed on a monitored server, CVE-2026-56265 will appear in your dashboard with remediation steps.

Related Docker CVEs

CVE-2026-57572CVSS 10Crawl4AI is an open-source LLM-friendly web crawler and scraper. Prior to 0.9.0, the Docker API server accepted request-supplied browser_config.extra_args, which flowed into Chromium's launch arguments. An attacker could inject Chromium switches that replace a child-process launch command together with --no-zygote, causing Chromium to fork or exec an attacker-controlled command as the container's runtime user. The Docker API is unauthenticated by default, so a single request yields arbitrary command execution. This issue is fixed in version 0.9.0.
CVE-2026-26216CVSS 10Crawl4AI versions prior to 0.8.0 contain a remote code execution vulnerability in the Docker API deployment. The /crawl endpoint accepts a hooks parameter containing Python code that is executed using exec(). The __import__ builtin was included in the allowed builtins, allowing unauthenticated remote attackers to import arbitrary modules and execute system commands. Successful exploitation allows full server compromise, including arbitrary command execution, file read and write access, sensitive data exfiltration, and lateral movement within internal networks.
CVE-2026-44329CVSS 10free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's SMF mounts the UPI management route group without OAuth2/bearer-token authorization middleware. A network attacker who can reach SMF on the SBI can hit UPI endpoints with no Authorization header at all, and the requests reach the SMF business handlers. In the running Docker lab this was directly demonstrated for read (GET /upi/v1/upNodesLinks), write (POST /upi/v1/upNodesLinks with attacker-controlled UP-node and link payload), and delete (DELETE /upi/v1/upNodesLinks/{nodeID}) operations. This vulnerability is fixed in 4.2.2.
CVE-2026-42298CVSS 10Postiz is an AI social media scheduling tool. Prior to commit da44801, a "Pwn Request" vulnerability in the Build and Publish PR Docker Image workflow (.github/workflows/pr-docker-build.yml) allows any unauthenticated user to execute arbitrary code during the Docker build process and exfiltrate a highly privileged GITHUB_TOKEN (write-all permissions). This can be achieved simply by opening a Pull Request from a fork with a maliciously modified Dockerfile.dev. This issue has been patched via commit da44801.
CVE-2026-40281CVSS 10Gotenberg is a Docker-powered stateless API for PDF files. In versions 8.30.1 and earlier, the metadata write endpoint validates metadata keys for control characters but leaves metadata values unsanitized. A newline character in a metadata value splits the ExifTool stdin line into two separate arguments, allowing injection of arbitrary ExifTool pseudo-tags such as -FileName, -Directory, -SymLink, and -HardLink. This is a bypass of the incomplete key-sanitization fix introduced in v8.30.1. An unauthenticated attacker can rename or move any PDF being processed to an arbitrary path in the container filesystem, overwrite arbitrary files, or create symlinks and hard links at arbitrary paths.

References

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