7.5highHigh
CVE-2026-42570
Svelte Devalue
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.
Exploitation status
- A vendor advisory or patch reference has been published.
What the metrics mean
- It is reachable over a network, without needing local access.
- For an attacker who can reach it, no special conditions are needed to exploit it.
- To exploit it, no account is needed.
- Beyond that, no action by a user is required.
Scoring
- CVSS
- 7.5 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H- Weakness
- CWE-770
- Assigned by
- security-advisories@github.com
Dates
- Published
- 2026-06-09
- Last modified
- 2026-08-24
- Sources
- NVD
Affected products
- Svelte Devalue5.6.3 - 5.8.1
As listed in the NVD configuration data. Not a statement about your estate.
References
- https://github.com/sveltejs/devalue/commit/206ca6712fbc380a4571c59de9ab04b91110792d
- https://github.com/sveltejs/devalue/releases/tag/v5.8.1
- https://github.com/sveltejs/devalue/security/advisories/GHSA-77vg-94rm-hx3p
- 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