---
title: "CVE-2025-61622: Apache Pyfory python is vulnerable to deserialization of untrusted data"
url: https://erroneo.us/security/cve/CVE-2025-61622/
description: "CVE-2025-61622 (pyfory (PyPI)): Deserialization of untrusted data in python in pyfory versions 0.12.0 through 0.12.2, or the legacy pyfury versions from…"
type: vulnerability-record
section: "Security Digest"
date_published: 2025-10-01
date_modified: 2025-11-05
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2025-61622"
kev: false
cvss: 9.8
epss: 0.45125
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2025-61622: Apache Pyfory python is vulnerable to deserialization of untrusted data

**Signal:** High exploit likelihood. EPSS ranks it in the top 5% of all CVEs for likely exploitation in the next 30 days. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 45.1% , percentile 99: FIRST’s model estimates a 45.1% chance of exploitation activity in the next 30 days, higher than 99% of all scored CVEs (very high). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes pyfory (PyPI) >= 0.12.0, < 0.12.3, fixed in 0.12.3 ; pyfury (PyPI) >= 0.1.0, <= 0.10.3, no fixed version listed . Check your lockfile, including transitive dependencies.

## What it is

Deserialization of untrusted data in python in pyfory versions 0.12.0 through 0.12.2, or the legacy pyfury versions from 0.1.0 through 0.10.3: allows arbitrary code execution. An application is vulnerable if it reads pyfory serialized data from untrusted sources. An attacker can craft a data stream that selects pickle-fallback serializer during deserialization, leading to the execution of pickle.loads, which is vulnerable to remote code execution. Users are recommended to upgrade to pyfory version 0.12.3 or later, which has removed pickle fallback serializer and thus fixes this issue.

## Affected packages

- PyPI `pyfory` >= 0.12.0, < 0.12.3 → fixed: 0.12.3
- PyPI `pyfury` >= 0.1.0, <= 0.10.3 → fixed: none listed

## Affected products (CVE record)

- Apache Software Foundation Apache Fory: 0.12.0 <= 0.12.2
- Apache Software Foundation Apache Fory: 0.1.0 <= 0.10.3

## Severity

- CISA-ADP CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 45.12% probability of exploitation activity in the next 30 days; percentile 99.

## Sources

- [lists.apache.org](https://lists.apache.org/thread/vfn9hp9qt06db5yo1gmj3l114o3o2csd)
- [GitHub Advisory GHSA-538v-3wq9-4h3r](https://github.com/advisories/GHSA-538v-3wq9-4h3r)
- [CVE.org record CVE-2025-61622](https://www.cve.org/CVERecord?id=CVE-2025-61622)
- [NVD entry CVE-2025-61622](https://nvd.nist.gov/vuln/detail/CVE-2025-61622)
- [openwall.com](http://www.openwall.com/lists/oss-security/2025/09/29/3)
- [github.com](https://github.com/apache/fory/pull/2629)
- [github.com](https://github.com/apache/fory/commit/379b948ecae5c3b849e5bdb3997978c9a163e40b)
- [github.com](https://github.com/apache/fory/releases/tag/v0.12.3)

---
Source page: https://erroneo.us/security/cve/CVE-2025-61622/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt