CVE-2026-31815

Component state manipulation is possible in django-unicorn due to missing access control checks during property updates and method calls. An attacker can bypass the intended _is_public protection to modify internal attributes such as template_name or trigger protected methods.

Vulnerability Details: Component Access Control Bypass

Security analysis identified that the framework fails to enforce visibility boundaries defined by _is_public within the action parsers. Specifically, the logic in set_property_value() and _call_method_name() utilizes getattr and setattr directly on component instances without verifying if the target attribute or method is explicitly marked as public.

Vulnerability resides in:

• src/django_unicorn/views/action_parsers/call_method.py
• src/django_unicorn/views/action_parsers/utils.py

While Django's template engine restricts rendering to registered directories, an unauthorized user can still force a component to render sensitive templates (e.g., admin layouts) from other installed applications or reset the component state by invoking the internal reset() method.

Proof of Concept (PoC)

Attacker can overwrite the template_name attribute by sending a crafted JSON payload to the message endpoint:

1. Construct a payload targeting a protected attribute:

   {
     "actionQueue": [
       {
         "type": "syncInput",
         "payload": { "name": "template_name", "value": "admin/base.html" }
       }
     ],
     "data": {},
     "meta": "<checksum_of_empty_dict>"
   }
   

2. The server-side component updates its internal state: self.template_name = "admin/base.html".
3. Subsequent re-rendering displays the content of the targeted template, bypassing intended component logic.

Low severity. The risk is limited to unauthorized manipulation of component state and rendering of existing templates within the application's configured template directories. Remote Code Execution (RCE) is not possible via this vector.

CVE-2026-31815 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 (0.67.0); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2026-31815? CVE-2026-31815 is a medium-severity security vulnerability in django-unicorn (pip), affecting versions < 0.67.0. It is fixed in 0.67.0.
2. How severe is CVE-2026-31815? CVE-2026-31815 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 django-unicorn are affected by CVE-2026-31815? django-unicorn (pip) versions < 0.67.0 is affected.
4. Is there a fix for CVE-2026-31815? Yes. CVE-2026-31815 is fixed in 0.67.0. Upgrade to this version or later.
5. Is CVE-2026-31815 exploitable, and should I be worried? Whether CVE-2026-31815 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-2026-31815 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-2026-31815? Upgrade django-unicorn to 0.67.0 or later.