# CVE-2019-1010083: Pallets Project Flask is vulnerable to Denial of Service via Unexpected memory usage

Source: https://junglewise.ai/threats/cve-2019-1010083-pallets-project-flask-is-vulnerable-to-denial-of-service-via  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2019-07-17  
License: CC BY 4.0 with a link back

CVE-2019-1010083 · Severity: low · CVSS 3.1 · Published 2019-07-17

The Pallets Project Flask before 1.0 is affected by: unexpected memory usage. The impact is: denial of service. The attack vector is: crafted encoded JSON data. The fixed version is: 1. NOTE: this may overlap CVE-2018-1000656.

Technologies: [flask (PyPI)](https://junglewise.ai/threats/technologies/flask). Vendors: [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2019-1010083 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2019-1010083 being exploited in the wild.

**How severe is CVE-2019-1010083?** Low severity, with a CVSS score of 3.1, published 17 July 2019.

**Which products and versions are affected?** flask (PyPI) ECOSYSTEM:introduced=0,fixed=1.0.

**Is there a fix for CVE-2019-1010083?** Yes. flask (PyPI): upgrade to 1.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2019-1010083?** Check whether you run flask (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- flask (PyPI): upgrade to 1.0 or later

  ```sh
  pip install "flask>=1.0"
  ```


## Affected products

- flask (PyPI) ECOSYSTEM:introduced=0,fixed=1.0

## Identifiers

- CVE-2019-1010083
- GHSA-5wv5-4vpf-pj6m
- PYSEC-2019-179

## Related threats

- [PYSEC-2026-1377 - Flask uses fallback key instead of current signing key](https://junglewise.ai/threats/cve-2025-47278-flask-uses-fallback-key-instead-of-current-signing-key)
- [Flask session does not add `Vary: Cookie` header when accessed in some ways](https://junglewise.ai/threats/cve-2026-27205-flask-session-does-not-add-vary-cookie-header-when-accessed-in)
- [Flask vulnerable to possible disclosure of permanent session cookie due to missing Vary: Cookie header](https://junglewise.ai/threats/cve-2023-30861-flask-vulnerable-to-possible-disclosure-of-permanent-session)
- [Flask is vulnerable to Denial of Service via incorrect encoding of JSON data](https://junglewise.ai/threats/cve-2018-1000656-flask-is-vulnerable-to-denial-of-service-via-incorrect-encoding)