high7.5
CVE-2026-42570
Svelte devalue is a JavaScript library that serializes values into strings when JSON.stringify isn't sufficient for the job.
Impact
Svelte devalue is a JavaScript library that serializes values into strings when JSON.stringify isn't sufficient for the job. From version 5.6.3 to before version 5.8.1, devalue.parse could, due to quirks in some JavaScript engines, be convinced to allocate much more memory than was needed when deserializing sparse arrays, leading to excessive memory consumption. This issue has been patched in version 5.8.1.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | devalue | >= 5.6.3, <= 5.8.0 | 5.8.1 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Svelte | Devalue | from 5.6.3 before 5.8.1 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-77vg-94rm-hx3p
- https://github.com/sveltejs/devalue/security/advisories/GHSA-77vg-94rm-hx3p
- https://github.com/sveltejs/devalue/commit/206ca6712fbc380a4571c59de9ab04b91110792d
- https://github.com/sveltejs/devalue/releases/tag/v5.8.1
- https://nvd.nist.gov/vuln/detail/CVE-2026-42570
- https://access.redhat.com/errata/RHSA-2026:37272
- https://access.redhat.com/errata/RHSA-2026:57590
- https://access.redhat.com/security/cve/CVE-2026-42570
- https://bugzilla.redhat.com/show_bug.cgi?id=2487050
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42570.json