---
title: "CVE-2023-47204: transmute-core unsafe YAML deserialization vulnerability"
url: https://erroneo.us/security/cve/CVE-2023-47204/
description: "CVE-2023-47204 (transmute-core (PyPI)): Unsafe YAML deserialization in yaml.Loader in transmute-core before 1.13.5 allows attackers to execute arbitrary…"
type: vulnerability-record
section: "Security Digest"
date_published: 2023-11-02
date_modified: 2024-11-18
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2023-47204"
kev: false
cvss: 9.3
epss: 0.00802
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2023-47204: transmute-core unsafe YAML deserialization vulnerability

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (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 0.8% , percentile 56: FIRST’s model estimates a 0.8% chance of exploitation activity in the next 30 days, higher than 56% of all scored CVEs (moderate). 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 transmute-core (PyPI) >= 0, < 1.13.5, fixed in 1.13.5 . Check your lockfile, including transitive dependencies.

## What it is

Unsafe YAML deserialization in yaml.Loader in transmute-core before 1.13.5 allows attackers to execute arbitrary Python code.

## Affected packages

- PyPI `transmute-core` >= 0, < 1.13.5 → fixed: 1.13.5

## Affected products (CVE record)

- n/a n/a: see advisory

## 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 4.0: 9.3 `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.80% probability of exploitation activity in the next 30 days; percentile 56.

## Sources

- [GitHub Advisory GHSA-w9cp-3x79-2p8p](https://github.com/advisories/GHSA-w9cp-3x79-2p8p)
- [CVE.org record CVE-2023-47204](https://www.cve.org/CVERecord?id=CVE-2023-47204)
- [NVD entry CVE-2023-47204](https://nvd.nist.gov/vuln/detail/CVE-2023-47204)
- [github.com](https://github.com/toumorokoshi/transmute-core/releases/tag/v1.13.5)
- [github.com](https://github.com/toumorokoshi/transmute-core/pull/58)
- [github.com](https://github.com/toumorokoshi/transmute-core/commit/29bf82eb8ed9926d31eec90aec482ecc0dcb23f0)
- [github.com](https://github.com/pypa/advisory-database/tree/main/vulns/transmute-core/PYSEC-2023-223.yaml)

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Source page: https://erroneo.us/security/cve/CVE-2023-47204/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt