Description
Heym before 0.0.53 evaluates workflow condition expressions using Python's eval() with insufficient sandboxing in the workflow executor service. Authenticated users can edit workflow condition nodes or import malicious templates to execute arbitrary Python and OS commands as the backend process user.
Published: 2026-09-27
Score: 8.7 High
EPSS: < 1% Very Low
KEV: No
Impact: Remote code execution
Action: Immediate Patch
AI Analysis

Impact

Heym before 0.0.53 evaluates workflow condition expressions using Python's eval() without sufficient sandboxing in the workflow executor service. Authenticated users can edit workflow condition nodes or import malicious templates, enabling them to execute arbitrary Python and OS commands as the backend process user. This flaw provides remote code execution with full system privileges.

Affected Systems

The vulnerabilities affect all instances of the Heym application running any release before 0.0.53, including versions 0.0.0 through 0.0.52. Users of these versions should verify the application level and any custom workflow definitions for the exposed conditions and webhook configurations.

Risk and Exploitability

The CVSS score of 8.7 indicates high severity, and the EPSS score is <1%, showing a low probability of exploitation at present. The vulnerability is not listed in the CISA KEV catalog. Based on the description, the likely attack vector is a remote actor who can edit workflow condition nodes or import malicious templates via an authenticated session. By triggering the vulnerable eval(), the attacker can execute arbitrary Python and OS commands as the backend process user, potentially compromising the entire system.

Generated by OpenCVE AI on September 27, 2026 at 17:28 UTC.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Apply the latest heym release (0.0.53 or later) to remove the eval() vulnerability.
  • Restrict workflow condition node editing to users with administrative privileges or enforce strict input validation for condition expressions.
  • Monitor workflow execution logs for suspicious activity that may indicate unauthorized code execution.

Generated by OpenCVE AI on September 27, 2026 at 17:28 UTC.

Tracking

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Advisories

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History

Tue, 29 Sep 2026 04:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Sun, 27 Sep 2026 17:30:00 +0000

Type Values Removed Values Added
References

Sun, 27 Sep 2026 16:45:00 +0000

Type Values Removed Values Added
Description Heym before 0.0.53 contains multiple independent vulnerabilities. (1) The workflow condition evaluator uses Python eval() without an effective sandbox, allowing any user who can edit a workflow branch/condition node — or who can import a workflow template containing a malicious condition node — to execute arbitrary Python code as the backend process user when the workflow runs. (2) Slack webhook signature verification and (3) Telegram webhook secret-token verification fail open when the trigger node has no credentialId or an empty signing secret, allowing anyone who knows the public webhook URL to trigger workflows with the owner's credentials without authentication. (4) The OAuth authorization endpoint does not validate the redirect_uri scheme, so an attacker who registers a public OAuth client with a javascript: or data: redirect_uri and lures a victim to the consent screen receives the authorization code and executes attacker-controlled JavaScript in the Heym origin, including access to the victim's HttpOnly auth cookie. (5) WorkflowExecutionToken, PortalSession, HITLRequest.public_token, and OAuthAuthorizationCode values are stored in plaintext, so any database read exposure yields valid scoped bearer tokens, including portal and HITL tokens with a 168-hour TTL that permit workflow execution on behalf of the owner. Heym before 0.0.53 evaluates workflow condition expressions using Python's eval() with insufficient sandboxing in the workflow executor service. Authenticated users can edit workflow condition nodes or import malicious templates to execute arbitrary Python and OS commands as the backend process user.
Title Heym before 0.0.53 Multiple RCE and Authentication Bypass Vulnerabilities Heym before 0.0.53 Remote Code Execution via eval() Sandbox Escape
References

Sun, 27 Sep 2026 04:30:00 +0000

Type Values Removed Values Added
First Time appeared Heymrun
Heymrun heym
Vendors & Products Heymrun
Heymrun heym

Sun, 27 Sep 2026 02:00:00 +0000

Type Values Removed Values Added
Description Heym before 0.0.53 contains multiple independent vulnerabilities. (1) The workflow condition evaluator uses Python eval() without an effective sandbox, allowing any user who can edit a workflow branch/condition node — or who can import a workflow template containing a malicious condition node — to execute arbitrary Python code as the backend process user when the workflow runs. (2) Slack webhook signature verification and (3) Telegram webhook secret-token verification fail open when the trigger node has no credentialId or an empty signing secret, allowing anyone who knows the public webhook URL to trigger workflows with the owner's credentials without authentication. (4) The OAuth authorization endpoint does not validate the redirect_uri scheme, so an attacker who registers a public OAuth client with a javascript: or data: redirect_uri and lures a victim to the consent screen receives the authorization code and executes attacker-controlled JavaScript in the Heym origin, including access to the victim's HttpOnly auth cookie. (5) WorkflowExecutionToken, PortalSession, HITLRequest.public_token, and OAuthAuthorizationCode values are stored in plaintext, so any database read exposure yields valid scoped bearer tokens, including portal and HITL tokens with a 168-hour TTL that permit workflow execution on behalf of the owner.
Title Heym before 0.0.53 Multiple RCE and Authentication Bypass Vulnerabilities
Weaknesses CWE-94
References
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}

Subscriptions

Heymrun Heym
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-09-28T13:40:50.761Z

Reserved: 2026-09-27T00:20:54.407Z

Link: CVE-2026-100865

cve-icon Vulnrichment

Updated: 2026-09-28T13:40:27.575Z

cve-icon NVD

Status : Deferred

Published: 2026-09-27T02:17:26.410

Modified: 2026-09-28T20:57:50.143

Link: CVE-2026-100865

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-27T17:30:17Z

Weaknesses
  • CWE-94

    Improper Control of Generation of Code ('Code Injection')