Vulnerability in Sveltejs Devalue
CVE-2026-123562
devalue (sveltejs/devalue) 5.8.0 before 5.9.3 contains an unhandled promise rejection in stringifyAsync: when serializing multiple promises, a later promise rejecting before an earlier one settles leaves an internal rejection unhandled, even if the caller catches the returned promise. An attacker able to influence the timing or failure of serialized asynchronous values can terminate the Node.js process.
Published .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/sveltejs/devalue/security/advisories/GHSA-x5rw-q4pp-hg5g (vendor-advisory)
- www.vulncheck.com/advisories/devalue-5.8.0-before-5.9.3-denial-of-service-via-s… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-123562?
- CVE-2026-123562 is a high-severity vulnerability in Sveltejs Devalue, classified under CWE-248. CVSS score: 7.5/10. Published 2026-11-08.
- How severe is CVE-2026-123562?
- High severity. CVSS v3 base score is 7.5 out of 10.