CVE-2026-21892

Affected Product: Parsl (Python Parallel Scripting Library)

Component: parsl.monitoring.visualization

Vulnerability Type: SQL Injection (CWE-89)

Severity: High (CVSS Rating Recommended: 7.5 - 8.6)

URL: https://github.com/Parsl/parsl/blob/master/parsl/monitoring/visualization/views.py

Summary

A SQL Injection vulnerability exists in the parsl-visualize component of the Parsl library. The application constructs SQL queries using unsafe string formatting (Python % operator) with user-supplied input (workflow_id) directly from URL routes. This allows an unauthenticated attacker with access to the visualization dashboard to inject arbitrary SQL commands, potentially leading to data exfiltration or denial of service against the monitoring database.

Root Cause Analysis

The vulnerability is located in parsl/monitoring/visualization/views.py. Multiple route handlers take the workflow_id parameter from the URL and inject it directly into a raw SQL query string without sanitization or parameterization.

Vulnerable Code Snippet 1

   query = """SELECT task.task_id, task.task_func_name, task.task_depends, status.task_status_name
               FROM task LEFT JOIN status
               ON task.task_id = status.task_id
               AND task.run_id = status.run_id
               AND status.timestamp = (SELECT MAX(status.timestamp)
                                       FROM status
                                       WHERE status.task_id = task.task_id and status.run_id = task.run_id
                                      )
               WHERE task.run_id='%s'""" % (workflow_id)

Vulnerable Code Snippet 2

df_task_tries = pd.read_sql_query("""SELECT ...
                                     WHERE task.task_id = try.task_id AND task.run_id='%s' and try.run_id='%s'"""
                                     % (workflow_id, workflow_id), db.engine) # <--- Vulnerable 

Impact

Data Exfiltration: An attacker can use UNION based injection to dump the entire contents of the monitoring database, including potentially sensitive environment variables, task parameters, or host information logged by the monitoring system.

Access Control Bypass: By injecting boolean logic (e.g., ' OR '1'='1), an attacker could bypass specific workflow filters to view data they are not authorized to see.

Denial of Service: Time-based attacks or resource-intensive queries (e.g., randomblob) could crash the visualization server or the database.

Proof of Concept (PoC)

Prerequisites:

Parsl installed with monitoring enabled (pip install 'parsl[monitoring,visualization]').

A running parsl-visualize server serving a database with at least one recorded workflow.

Reproduction Steps:

Identify a valid workflow ID (or use a known ID like default-run or a UUID).

Navigate to the dag_group_by_states endpoint using the following manipulated URLs to confirm SQL logic control (Boolean-based Blind SQLi).

Test 1: Boolean FALSE (Graph Disappears)
Injecting a false condition (1=0) causes the query to return zero rows, resulting in an empty visualization.

http://<server>:8080/workflow/<VALID_ID>'%20AND%20'1'='0/dag_group_by_states

Test 2: Boolean TRUE (Graph Reappears)
Injecting a true condition (1=1) restores the query logic, causing the graph to render correctly.

http://<server>:8080/workflow/<VALID_ID>'%20AND%20'1'='1/dag_group_by_states

Untrusted input alters a database query, allowing the attacker to read or modify data the query was not intended to access. Typical impact: data disclosure or modification.

CVE-2026-21892 has a CVSS score of 5.3 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2026.01.05); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2026-21892? CVE-2026-21892 is a medium-severity SQL injection vulnerability in parsl (pip), affecting versions < 2026.01.05. It is fixed in 2026.01.05. Untrusted input alters a database query, allowing the attacker to read or modify data the query was not intended to access.
2. How severe is CVE-2026-21892? CVE-2026-21892 has a CVSS score of 5.3 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of parsl are affected by CVE-2026-21892? parsl (pip) versions < 2026.01.05 is affected.
4. Is there a fix for CVE-2026-21892? Yes. CVE-2026-21892 is fixed in 2026.01.05. Upgrade to this version or later.
5. Is CVE-2026-21892 exploitable, and should I be worried? Whether CVE-2026-21892 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-21892 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-21892? Upgrade parsl to 2026.01.05 or later.