devalue: `stringify`/`uneval` serialize shared memory (CVE-2026-92708)

What is affected, what to do

A flaw was found in devalue, a JavaScript library for serializing values. The `stringify` and `uneval` functions incorrectly serialize Node Buffers by emitting the entire backing `ArrayBuffer` instead of only the view.

The available sources name no fixed version. Check the vendor guidance in the references below.

Affected

• Sveltejs Devalue gte 5.1.0, < 5.9.3..*

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Metrics

Detection rules

No NEOSEC detection rule is available for this vulnerability yet.

Classification under NIS2 and CRA

Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

NIS2

NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

Read in glossary

High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.

CRA

The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

Read in glossary

From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.

ISO/IEC 27001

ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

Read in glossary

Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

Description

A flaw was found in devalue, a JavaScript library for serializing values. The `stringify` and `uneval` functions incorrectly serialize Node Buffers by emitting the entire backing `ArrayBuffer` instead of only the view. This vulnerability allows for the disclosure of up to 64 KB of unrelated process memory, potentially including sensitive data from other in-flight requests, without authentication. This can occur in server-side-rendered frameworks when a public page processes a small Buffer.

Source: redhat_csaf, OSV (Open Source Vulnerabilities), GitHub Security Advisories, ENISA EUVD, cvelistv5, NVD (NIST)

Vendors and products

• Sveltejs Devalue

Weakness classes (CWE)

• CWE-200Exposure of Sensitive Information to an Unauthorized Actor

  Class

  The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.

  Entry at MITRE CWE-200

• CWE-226Sensitive Information in Resource Not Removed Before Reuse

  Base

  The product releases a resource such as memory or a file so that it can be made available for reuse, but it does not clear or "zeroize" the information contained in the resource before the product performs a critical state transition or makes the resource available for reuse by other entities.

  Entry at MITRE CWE-226

References & sources

• github.comsveltejs/devalue/security/advisories/GHSA-j22f-vq7h-c4qmx_refsource_CONFIRM, euvd
• github.comsveltejs/devalue/commit/46dc877b3570dafb1cd3291b9bb48cecef8f7266x_refsource_MISC, euvd
• github.comsveltejs/devalue/releases/tag/v5.9.3x_refsource_MISC, euvd
• NVD (NIST)vuln/detail/CVE-2026-92708advisory
• github.comsveltejs/devaluepackage

Changes to this CVE

Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

1. 23.09.2026Record modifiedCISA ADP

   CISA assessment (SSVC): exploitation: none known, automatable: yes

   Show the original change

   Individual changes of this event as published by NVD

   Type	Action	Before	After
   SSVC assessment	added	—	{"id":"CVE-2026-92708","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"partial"}],"version":"2.0.3","timestamp":"2026-09-23T19:38:28.127737Z"}

   Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0

2. 18.09.2026ReceivedGitHub

   CVSS V3.1: AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

   Weakness type: CWE-200, CWE-226

   Description added or changed

   New references:

   • https://github.com/sveltejs/devalue/commit/46dc877b3570dafb1cd3291b9bb48cecef8f7266
   • https://github.com/sveltejs/devalue/releases/tag/v5.9.3
   • https://github.com/sveltejs/devalue/security/advisories/GHSA-j22f-vq7h-c4qm
   Show 8 original changes

   Individual changes of this event as published by NVD

   Type	Action	Before	After
   Description	added	—	Svelte devalue is a JavaScript library that serializes values into strings when JSON.stringify isn't sufficient for the job. In versions 5.1.0 through 5.9.2, stringify and uneval functions serialize a typed array by emitting its entire backing ArrayBuffer rather than only the view, so serializing a Node Buffer, whose backing store is a process-wide shared pool, discloses up to 64 KB of unrelated process memory, including bytes from other in-flight requests. In a server-side-rendered framework such as SvelteKit or Nuxt, a public page whose load() returns a small Buffer, or that reads a small file, can therefore ship another user's request body or Authorization header in its HTML without authentication. Because this occurs during serialization, it fires on every such render and is not mitigated by the parse/unflatten prototype-pollution and denial-of-service guards, which only apply when parsing untrusted input. As a workaround, convert Node Buffer objects to Uint8Array before serialization. This issue has been fixed in version 5.9.3.
   CVSS	added	—	AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
   Weakness type (CWE)	added	—	CWE-200
   Weakness type (CWE)	added	—	CWE-226
   Affected versions (publisher)	added	—	New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/92xxx/CVE-2026-92708.json">CVE-2026-92708</a>
   Reference	added	—	https://github.com/sveltejs/devalue/commit/46dc877b3570dafb1cd3291b9bb48cecef8f7266
   Reference	added	—	https://github.com/sveltejs/devalue/releases/tag/v5.9.3
   Reference	added	—	https://github.com/sveltejs/devalue/security/advisories/GHSA-j22f-vq7h-c4qm

   Source identifier: security-advisories@github.com