CVE-2026-123569

8.7 highEPSS 0.3%Fix available

High (8.7) in sveltejs devalue. EPSS 0.3% estimated probability of exploitation activity in the next 30 days. Fixed in devalue 5.6.3.

The devalue package for npm before 5.6.3 can consume excessive CPU and memory when serializing sparse arrays with uneval or stringify. An attacker who manages to get a sparse array created on the server, which mainstream wire formats do not allow, and serialized there can cause a denial of service.

Severity

CVSS 4.0

8.7 high

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS 3.1

7.5 high

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS: 0.3% estimated probability of exploitation activity in the next 30 days; 28th percentile. Scored 2026-11-10. A forecast for this CVE across the internet, not for your own systems.
CWE: CWE-770 Allocation of Resources Without Limits or Throttling
Published: 2026-11-08 02:16 UTC
NVD analysis: Awaiting analysis
Record from: the NVD, synced 2026-11-08 02:40 UTC

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Affected

sveltejs:devalue

Versions

From the CNA's record in the CVE List.

Product	Affected
sveltejs devalue	before 5.6.3

Packages (OSV)

Advisory	Ecosystem	Package	Affected	Fixed in
GHSA-33hq-fvwr-56pm	npm	devalue	<5.6.3	5.6.3

Attack patterns (CAPEC)

The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits. More on the page of CWE-770 (20).

References

Check your stack JSON