Deserialization of Untrusted Data Affecting seroval package, versions <1.6.8
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published27 Oct 2026
- disclosed26 Oct 2026
- creditRyan Cruz
Introduced: 26 Oct 2026
NewCVE-2026-116580 (opens in a new tab)How to fix?
Upgrade seroval to version 1.6.8 or higher.
Overview
seroval is a Stringify JS values
Affected versions of this package are vulnerable to Deserialization of Untrusted Data via the sequence serialization logic in packages/seroval/src/core/sequence.ts, where identity of internal Sequence objects was checked by the presence of a __SEROVAL_SEQUENCE__ key rather than by instanceof. An attacker can supply a plain object with a __SEROVAL_SEQUENCE__ key and controlled t and d fields, causing the serializer to treat it as a trusted internal value and embed arbitrary code into the serialized output.
Details
Serialization is a process of converting an object into a sequence of bytes which can be persisted to a disk or database or can be sent through streams. The reverse process of creating object from sequence of bytes is called deserialization. Serialization is commonly used for communication (sharing objects between multiple hosts) and persistence (store the object state in a file or a database). It is an integral part of popular protocols like Remote Method Invocation (RMI), Java Management Extension (JMX), Java Messaging System (JMS), Action Message Format (AMF), Java Server Faces (JSF) ViewState, etc.
Deserialization of untrusted data (CWE-502) is when the application deserializes untrusted data without sufficiently verifying that the resulting data will be valid, thus allowing the attacker to control the state or the flow of the execution.