# CVE-2026-108378: dataclasses-avroschema code injection in docstring rendering

Source: https://junglewise.ai/threats/cve-2026-108378-dataclasses-avroschema-generates-avro-schemas-from-python  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-13. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-108378 · Severity: high · CVSS 8.8 · Published 2026-10-13

dataclasses-avroschema is a library that generates Python code from Avro schemas. Versions 0.40.0 through 0.70.5 fail to properly escape special characters when injecting schema documentation into generated Python class docstrings. An attacker who controls an Avro schema can inject malicious Python code that executes when the generated module is imported, potentially leading to arbitrary code execution.

Technologies: [Marcosschroh Dataclasses-Avroschema](https://junglewise.ai/threats/technologies/marcosschroh-dataclasses-avroschema). Vendors: [Marcosschroh](https://junglewise.ai/threats/vendors/marcosschroh).

## Quick answers

**Is CVE-2026-108378 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-108378 being exploited in the wild.

**How severe is CVE-2026-108378?** High severity, with a CVSS score of 8.8, published 13 October 2026.

**Which products and versions are affected?** Marcosschroh Dataclasses-Avroschema 0.40.0 through 0.70.5.

**Is there a fix for CVE-2026-108378?** Yes: fixed in 0.70.6. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-108378 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-108378?** Check whether you run Marcosschroh Dataclasses-Avroschema at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 0.70.6

## Technical details

The ClassRepresentation.render_docstring method copies doc values from Avro schema records into triple-quoted Python docstrings without escaping quotes or backslashes. A crafted doc value containing """ can prematurely close the docstring and inject code into the class body, while a trailing backslash can escape the closing delimiter. This affects the common use case of generating models from untrusted schemas fetched from shared registries.

## Affected products

- marcosschroh dataclasses-avroschema 0.40.0 through 0.70.5

## Timeline

- 2026-10-13: disclosed
- 2026-08-18: patched

## References

- [https://github.com/marcosschroh/dataclasses-avroschema/commit/429f3d705d2d04c0c65e2ef832daed5ff91318fc](https://github.com/marcosschroh/dataclasses-avroschema/commit/429f3d705d2d04c0c65e2ef832daed5ff91318fc)
- [https://github.com/marcosschroh/dataclasses-avroschema/releases/tag/0.70.6](https://github.com/marcosschroh/dataclasses-avroschema/releases/tag/0.70.6)

## Related threats

- [dataclasses-avroschema code injection in schema parsing](https://junglewise.ai/threats/cve-2026-108384-dataclasses-avroschema-generates-avro-schemas-from-python)
- [dataclasses-avroschema code injection in enum symbol rendering](https://junglewise.ai/threats/cve-2026-108382-dataclasses-avroschema-generates-avro-schemas-from-python)
- [dataclasses-avroschema code injection in generated annotations](https://junglewise.ai/threats/cve-2026-108381-dataclasses-avroschema-generates-avro-schemas-from-python)