vulnerability / NVI-00013208 / Revision 1
CyberChef: Prototype pollution in Series Chart operation
GitHub lists this reviewed advisory for cyberchef. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
5 medium
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
cyberchef
source listed< 11.2.0
On 5 June 2026 CyberChef received a security vulnerability report from @hyuunnn detailing a vulnerability in the Series Chart operation, where malicious input could result in prototype pollution of the data structures outputted from the operation. Other operations following Series Chart could have their behaviour manipulated by the attacker-controlled prototype, for example, injecting malicious content into their HTML output. In this case, a demonstration was provided that chained the Series Chart operation with the Parse UDP operation to cause attacker controlled JavaScript to be executed. ## Details When the Series Chart operation parses user-supplied CSV, it accepts `__proto__` as a key and uses it to pollute the object. The objToTbale function in src/core/lib/Protocol.mjs, used in a number of IP parsing operations, renders data items within `` tags without escaping. These bugs can be chained to produce an XSS vulnerability. **Proof of Concept** [https://gchq.github.io/CyberChef/#recipe=Series_chart('CRLF','Comma','',1,'')Parse_UDP('Raw')&input=X19wcm90b19fLDxpbWcgc3JjPXggb25lcnJvcj1hbGVydChkb2N1bWVudC5kb21haW4pPiwx](https://gchq.github.io/CyberChef/#recipe=Series_chart('
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
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04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
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- GHSA-fx6f-382r-j72c ↗
GitHub Advisory Database · vendor advisory
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Public revision history
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- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.