5.0
MEDIUM CVSS 3.1
CVE-2026-57439
CyberChef: Prototype pollution in Series Chart operation
Description

CyberChef is a web app for encryption, encoding, compression, and data analysis. Prior to 11.2.0, the Series Chart operation accepts __proto__ as a key while parsing user-supplied CSV, allowing prototype pollution that can be chained with operations such as Parse UDP to inject malicious JavaScript into HTML output. This issue is fixed in version 11.2.0.

INFO

Published Date :

July 8, 2026, 4:16 p.m.

Last Modified :

July 8, 2026, 4:16 p.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2026-57439 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Gchq cyberchef
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM [email protected]
Solution
Update CyberChef to version 11.2.0 or later to fix prototype pollution vulnerability.
  • Update CyberChef to version 11.2.0.
  • Apply patches or updates for CyberChef.
References to Advisories, Solutions, and Tools
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-57439 is associated with the following CWEs:

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-57439 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-57439 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Jul. 08, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'gchq', 'product': 'CyberChef', 'versions': [{'status': 'affected', 'version': '< 11.2.0'}]}]
    Added Description CyberChef is a web app for encryption, encoding, compression, and data analysis. Prior to 11.2.0, the Series Chart operation accepts __proto__ as a key while parsing user-supplied CSV, allowing prototype pollution that can be chained with operations such as Parse UDP to inject malicious JavaScript into HTML output. This issue is fixed in version 11.2.0.
    Added CVSS V3.1 AV:L/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
    Added CWE CWE-79
    Added CWE CWE-1321
    Added Reference https://github.com/gchq/CyberChef/commit/85db3be5d0096859b810f0e8d3e151d5dc9b948f
    Added Reference https://github.com/gchq/CyberChef/issues/2568
    Added Reference https://github.com/gchq/CyberChef/pull/2569
    Added Reference https://github.com/gchq/CyberChef/releases/tag/v11.2.0
    Added Reference https://github.com/gchq/CyberChef/security/advisories/GHSA-fx6f-382r-j72c
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.