---
title: "CVE-2024-34249: pywasm3 contains a heap buffer overflow which leads to segmentation fault"
url: https://erroneo.us/security/cve/CVE-2024-34249/
description: "CVE-2024-34249 (pywasm3 (PyPI)): wasm3 v0.5.0 was discovered to contain a heap buffer overflow which leads to segmentation fault via the function…"
type: vulnerability-record
section: "Security Digest"
date_published: 2024-05-06
date_modified: 2026-06-09
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2024-34249"
kev: false
cvss: 9.8
epss: 0.00706
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2024-34249: pywasm3 contains a heap buffer overflow which leads to segmentation fault

**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 0.7% , percentile 53: FIRST’s model estimates a 0.7% chance of exploitation activity in the next 30 days, higher than 53% 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 pywasm3 (PyPI) <= 0.5.0, no fixed version listed . Check your lockfile, including transitive dependencies.

## What it is

wasm3 v0.5.0 was discovered to contain a heap buffer overflow which leads to segmentation fault via the function "DeallocateSlot" in wasm3/source/m3compile.c.

## Affected packages

- PyPI `pywasm3` <= 0.5.0 → fixed: none listed

## 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 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 yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.71% probability of exploitation activity in the next 30 days; percentile 53.

## Sources

- [GitHub Advisory GHSA-mq9p-qw76-q6h7](https://github.com/advisories/GHSA-mq9p-qw76-q6h7)
- [CVE.org record CVE-2024-34249](https://www.cve.org/CVERecord?id=CVE-2024-34249)
- [NVD entry CVE-2024-34249](https://nvd.nist.gov/vuln/detail/CVE-2024-34249)
- [github.com](https://github.com/wasm3/wasm3/issues/485)
- [github.com](https://github.com/pypa/advisory-database/tree/main/vulns/pywasm3/PYSEC-2024-308.yaml)
- [github.com](https://github.com/wasm3/pywasm3/blob/main/wasm3/m3_compile.c#L420)

---
Source page: https://erroneo.us/security/cve/CVE-2024-34249/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt