dataclasses-avroschema: Code injection via schema field defaults in generated code
Summary
dataclasses-avroschema generates Python code from Avro schemas. In affected versions, string, UUID, bytes and fixed field defaults are written into generated string literals without escaping. A crafted schema default can close the literal and inject Python statements that run when the generated module is imported.
An attacker must get a crafted schema into the generator, for example via a schema registry, partner schema or external repository. This is not an internet-facing service, but the impact is code execution in the process that imports the generated module, such as a CI/CD job or data pipeline.
Affected
- dataclasses-avroschema from 0.38.0 through 0.70.5 (other sources list narrower or broader ranges; treat all versions before 0.70.6 as affected)
Fixed in
- Version 0.70.6
Workaround
- Unknown.
- Until patched, do not generate models from schemas from partners, external repositories or registries that have not been reviewed.
- Do not import generated modules from untrusted sources.
Exploitation
- CISA SSVC: exploitation status PoC, not automatable.
- No public proof of concept confirmed for this CVE; no evidence of exploitation in the wild found.
- CISA KEV: not listed according to the sources checked.
Our recommendation
- Upgrade dataclasses-avroschema to version 0.70.6 or later in all environments, including CI/CD and data pipelines, and verify the installed version.
- Also patch related advisory-family CVEs with the same upgrade (CVE-2026-108376, CVE-2026-108378, CVE-2026-108383, CVE-2026-108385).
- Review which schemas are fed into the generator and restrict them to trusted sources.
- Monitor pipelines for unexpected changes to generated modules.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- GitHub Security Advisory GHSA-9h8h-264x-jcg2 github.com
- Release 0.70.6 github.com
- Fix commit 01e6d5e github.com
- OSV CVE-2026-108375 osv.dev
- Tenable CVE-2026-108375 www.tenable.com
- VulDB 417852 vuldb.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 31 Oct 2026, 19:45.
Original description (NVD)
dataclasses-avroschema generates Avro schemas from Python dataclasses, Pydantic models, and Faust Records and generates Python code from Avro schemas. From version 0.38.0 through 0.70.5, FieldRepresentation.get_field_default inserts schema-controlled string, UUID, bytes, and fixed field defaults into quoted literals in generated Python source without escaping them. A crafted default can terminate the literal and inject statements into the generated module, which execute when the module is imported. Version 0.70.6 fixes the vulnerability by escaping schema values rendered into generated string literals.
NVD references (4)
- https://github.com/marcosschroh/dataclasses-avroschema/commit/01e6d5e15ab0ff69faac39a340d21b85da1e852f
- https://github.com/marcosschroh/dataclasses-avroschema/releases/tag/0.70.6
- https://github.com/marcosschroh/dataclasses-avroschema/security/advisories/GHSA-9h8h-264x-jcg2
- https://github.com/marcosschroh/dataclasses-avroschema/security/advisories/GHSA-9h8h-264x-jcg2
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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