CVE
Heym Unsandboxed skill code execution: skills run via a local backend subprocess without the Docker isolation that Python tools mandate
- Exploited
- No known exploitation
- Fix
- Fixed in 0.0.70
- Who is exposed
- Specific setups only
Do first: Check whether your setup matches what the bug needs. Agent Python skills run via a local backend subprocess without Docker isolation Backend runs as root in the container with the Docker socket mounted, as in the shipped Docker config A malicious skill is delivered via a shared workflow or template that another user imports and runs
- Last modified
- Whether it needs action now or is a reference record, by fixed rules, with why. Last checked is when cve.now last re-read it.What do these mean? →
- Reference
- Last checked
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 17/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
Heym, a self-hosted platform for agentic systems and business-process automation, does not run skill Python code in a Docker sandbox the way it does Python tools, so a skill runs inside the backend execution context with filesystem access, network access, and some environment variables it should not see. A user with low-privilege login can exploit this remotely over the network, and in the default Docker setup it can escalate to root on the host; the issue is fixed in version 0.0.70.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
Read the original description
Heym builds and runs agentic systems and business-process automations on self-hosted infrastructure. Prior to version 0.0.70, heym hardens one untrusted-code path but not its sibling. The Python tool executor (python_tool_executor.py) treats user code as untrusted and mandates a Docker sandbox (no network, read-only fs, non-root, no docker socket), failing closed. The skill executor (skill_python_executor.py) runs skill Python via a local backend subprocess with no Docker isolation — only a 512 MB RLIMIT and a 7-key env denylist — so a skill executes inside the backend execution context, with filesystem access, network egress, and non-denylisted environment variables that should not be exposed to untrusted/shared skills. In the shipped Docker config (backend runs as root + /var/run/docker.sock mounted), this escalates to host root. This issue has been patched in version 0.0.70.
Who should check
Teams running heym backends, especially in Docker with docker.sock mounted, and anyone who shares or imports skills, workflows or templates
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure8/25Specific setups only, reachable over the network
- Reach?/20Unknown. No tracked technology or package matched
- Severity8.8/10CVSS 8.8
- No patch0/5No signal
What would change the score
- Would score about 67 if added to CISA KEV
- Would score about 62 if CISA's SSVC rates exploitation active
- Would score about 24 if CISA's SSVC rates it automatable
What to do
Check whether your setup matches what the bug needs.
Agent Python skills run via a local backend subprocess without Docker isolation Backend runs as root in the container with the Docker socket mounted, as in the shipped Docker config A malicious skill is delivered via a shared workflow or template that another user imports and runsUpgrade to a fixed version: 0.0.70.
Check your systems with an agent
Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.
Check whether my systems are affected by CVE-2026-67543 (Heym Unsandboxed skill code execution: skills run via a local backend subprocess without the Docker isolation that Python tools mandate), using the cve.now data below.
Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.
What cve.now has for CVE-2026-67543 (entry last updated 2026-11-11):
Affected:
- heymrun heym: fixed in 0.0.70
Fixed versions: 0.0.70.
Conditions (all must be true for the bug to be hit):
- Agent Python skills run via a local backend subprocess without Docker isolation (source: https://github.com/heymrun/heym/security/advisories/GHSA-hcv7-mg77-pg73)
- Backend runs as root in the container with the Docker socket mounted, as in the shipped Docker config (source: https://github.com/heymrun/heym/security/advisories/GHSA-hcv7-mg77-pg73)
- A malicious skill is delivered via a shared workflow or template that another user imports and runs (source: https://github.com/heymrun/heym/security/advisories/GHSA-hcv7-mg77-pg73)
Setup: the bug is reachable in a default setup; no special feature or setting is needed.
Attacker needs: network access, low-privilege login, no user action.
CISA KEV: CVE-2026-67543 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-67543 only. If you also check another CVE, look up its own KEV status; never assume it from this one.
How to check:
- Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory.
Verify against the linked advisories before concluding, and cite the date you read each one:
- https://github.com/heymrun/heym/security/advisories/GHSA-hcv7-mg77-pg73
- https://github.com/heymrun/heym/commit/2155057f4153a1e3a7b789d104f7fa96e92964e5
- https://github.com/heymrun/heym/commit/28bb2901e4dea128ac493f67ee9478d230b7a3d7
- https://github.com/heymrun/heym/releases/tag/0.0.70
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.
Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.
Entry: https://cve.now/CVE-2026-67543
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example execute with name cve.get and arguments {"id": "CVE-2026-67543"}.Timeline
- CVE published
- First seen by cve.now
Affected versions
- heymrun heym
fixed in 0.0.70
Evidence 6
Vendor advisory · 1
Establishes: Affected and fixed versions.
- Advisory
CVE record · 2
Establishes: The identifier and description.
- Record
- Record
Other links · 3
- Repository
- Repository
- Repository
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-67543
Is CVE-2026-67543 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
Skill code runs without the Docker isolation that Python tools use, so it executes directly in the backend with access to the network, filesystem, and secrets. A malicious skill shared through a workflow or template runs in the backend of any user who imports and runs it. In the default Docker deployment, the backend runs as root with the Docker socket mounted, which can escalate to host root.Source: github.com
Which versions are affected by CVE-2026-67543?
heym: before 0.0.70.Source: cve.now feed data
Am I affected, and how do I check?
Heym versions before 0.0.70 are affected, per the fixed version in the affected range. Check the Heym version in use, and check whether agent Python skills run through a local backend subprocess rather than in Docker. Also check whether docker-compose.yml mounts /var/run/docker.sock and whether the backend runs as root in the container.Source: github.com
How do I fix CVE-2026-67543?
Upgrade to a fixed version: 0.0.70.Source: cve.now feed data