CVE-2026-92708 devalue: Cross-request process memory disclosure in devalue when `stringify` / `uneval` serialize Node Buffers
Attackers can read sensitive process memory, including other users' data, by triggering serialization of Node Buffers in SvelteKit or Nuxt applications.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-92708?
CVE-2026-92708 is a high-severity vulnerability in sveltejs devalue, published on 18 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-92708?
2 open source packages ship an affected version, including devalue.
| Package | Affected | Fixed in |
|---|---|---|
devalue npm | From 5.1.0 | 5.9.3 |
devalue npm | From 5.1.0 | 5.9.3 |
How do I fix CVE-2026-92708?
Upgrade devalue to 5.9.3 or later.
Is CVE-2026-92708 being exploited?
There is no known exploitation of CVE-2026-92708 in the wild and no public exploit code.
Sources
Also known as CLSA-2026-1790888210, CLSA-2026-1790937656, CLSA-2026-1790965180, GHSA-j22f-vq7h-c4qm.