# CVE-2026-64608: Apache Fory: Heap type confusion and out-of-bounds read/write in C++ compatible-mode field-skip paths

> Attackers can trigger heap type confusion and out-of-bounds memory access in Apache Fory C++ by sending crafted serialized data in compatible mode.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 21 Jul 2026
- **Updated:** 21 Jul 2026
- **Also known as:** GHSA-wh2x-66qr-23v8

## What is CVE-2026-64608?

CVE-2026-64608 is a critical unsafe deserialization vulnerability in Apache Fory, published on 21 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Heap type confusion and out-of-bounds read/write in the Apache Fory C++ implementation. When deserializing data in compatible mode, the field-skip paths do not correctly validate the declared field types against the actual data, so input with an inconsistent schema can cause type confusion and out-of-bounds memory access. Only the C++ implementation is affected; other language implementations of Apache Fory are not.

This issue affects Apache Fory C++: from 0.14.0 before 1.4.0.

Users are recommended to upgrade to version 1.4.0, which fixes the issue.

Weakness: CWE-843 (Access of Resource Using Incompatible Type), CWE-787 (Out-of-bounds Write), CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2026-64608?

It affects 1 product.


Products: Apache Fory.

## How do I fix CVE-2026-64608?

No fix has been published for CVE-2026-64608 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-64608 being exploited?

There is no known exploitation of CVE-2026-64608 in the wild and no public exploit code.

## Other vulnerabilities in Apache Fory

- [CVE-2026-71558](https://insights.sbomify.com/CVE-2026-71558/): Apache Fory: Heap type confusion in C++ polymorphic smart-pointer deserialization (critical 9.8)
- [CVE-2026-64606](https://insights.sbomify.com/CVE-2026-64606/): Apache Fory, Apache Fory: Class-registration bypass through an auto-admitted SerializedLambda capturing interface (critical 9.8)
- [CVE-2026-48207](https://insights.sbomify.com/CVE-2026-48207/): Apache Fory: PyFory ReduceSerializer Incomplete Policy Enforcement (critical 9.8)
- [CVE-2025-61622](https://insights.sbomify.com/CVE-2025-61622/): Apache Fory, Apache Fory: Python RCE via unguarded pickle fallback serializer in pyfory (critical 9.8)
- [CVE-2026-71560](https://insights.sbomify.com/CVE-2026-71560/): Apache Fory: Out-of-bounds heap read in C++ struct deserializer tagged-int fast-path (critical 9.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-64608 and fix it if it is affected.

What it is: CVE-2026-64608 is a critical unsafe deserialization vulnerability in Apache Fory, published on 21 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-64608 in the wild and no public exploit code.

Affected product: Apache Fory. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-64608/ (Markdown: https://insights.sbomify.com/CVE-2026-64608/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-64608
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64608
- OSV: https://osv.dev/vulnerability/CVE-2026-64608

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-64608/
Summaries are generated and may contain mistakes; the official description above is the record.