Back
CVE-2026-42570
Svelte devalue: DoS via sparse array deserialization
High7.5EPSS 0.40%
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
Description
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| redhat-SADPADP (enrichment) | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Modified | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.40% · top 66% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Weakness
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- npmdevalueGHSA-77vg-94rm-hx3p (opens in a new tab)
References (8)
- https://github.com/sveltejs/devalue/security/advisories/GHSA-77vg-94rm-hx3p (opens in a new tab)x_refsource_CONFIRM
- https://github.com/sveltejs/devalue/commit/206ca6712fbc380a4571c59de9ab04b91110792d (opens in a new tab)x_refsource_MISC
- https://github.com/sveltejs/devalue/releases/tag/v5.8.1 (opens in a new tab)x_refsource_MISC
- https://access.redhat.com/security/cve/CVE-2026-42570 (opens in a new tab)vdb-entryx_refsource_REDHAT
- RHBZ#2487050 (opens in a new tab)issue-trackingx_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42570.json (opens in a new tab)x_sadp-csaf-vex
- https://access.redhat.com/errata/RHSA-2026:57590 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:37272 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-77vg-94rm-hx3p (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-42570)Record last updated .