Cyber Resilience

CVE-2026-22774

DoS in Svelte Devalue 5.3.0 – 5.6.2

Published
15 January 2026
Modified
15 July 2026
Patch / advisory
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0057 44th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-22774 is a high-severity Amplification (CWE-405) vulnerability in Svelte Devalue. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 44th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SI-2 (Flaw Remediation) and SC-5 (Denial-of-service Protection) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-22774 is a denial-of-service vulnerability in the Svelte devalue JavaScript library, which serializes values into strings beyond the capabilities of JSON.stringify. Versions 5.3.0 through 5.6.1 are affected, where certain inputs to devalue.parse can trigger excessive CPU time or memory consumption. The root cause lies in the typed array hydration logic, which assumes an ArrayBuffer input without validation before creating the typed array, leading to resource exhaustion. This issue, rated at CVSS 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) and mapped to CWE-405 (Asymmetric Resource Consumption), impacts applications that invoke devalue.parse on untrusted data.

Attackers can exploit this vulnerability remotely without authentication or user interaction by supplying specially crafted inputs to affected applications. Any unauthenticated network attacker targeting a system parsing external data with devalue.parse could induce denial of service through CPU or memory exhaustion, disrupting service availability without compromising confidentiality or integrity.

Mitigation is available via an upgrade to devalue version 5.6.2, which addresses the validation flaw. The Svelte devalue security advisory (GHSA-vw5p-8cq8-m7mv) details the issue, while the release notes and fixing commit (e46afa64dd2b25aa35fb905ba5d20cea63aabbf7) confirm the patch implementation.

EU & UK References

Vulnerability Data

Svelte devalue is a JavaScript library that serializes values into strings when JSON.stringify isn't sufficient for the job. From 5.3.0 to 5.6.1, certain inputs can cause devalue.parse to consume excessive CPU time and/or memory, potentially leading to denial of service…

more

in systems that parse input from untrusted sources. This affects applications using devalue.parse on externally-supplied data. The root cause is the typed array hydration expecting an ArrayBuffer as input, but not checking the assumption before creating the typed array. This vulnerability is fixed in 5.6.2.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
Why these techniques?

Directly enables application exploitation leading to resource exhaustion DoS via untrusted parse input.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-22775Same product: Svelte Devalue
CVE-2026-42570Same product: Svelte Devalue
CVE-2026-30226Same product: Svelte Devalue
CVE-2026-22803Same vendor: Svelte
CVE-2026-42567Same vendor: Svelte
CVE-2026-40074Same vendor: Svelte
CVE-2025-8677Shared CWE-405
CVE-2026-24324Shared CWE-405
CVE-2025-30204Shared CWE-405
CVE-2025-68480Shared CWE-405

Affected Assets

svelte
devalue
5.3.0 — 5.6.2

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-2 Flaw Remediation
  • SI-10 Information Input Validation
  • SC-5 Denial-of-service Protection
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 6 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

prevent

Remediating the flaw by upgrading devalue to version 5.6.2 directly eliminates the typed array hydration vulnerability causing resource exhaustion.

prevent

Validating untrusted inputs prior to devalue.parse prevents specially crafted data from triggering excessive CPU or memory consumption in the hydration logic.

prevent

Implementing denial-of-service protections limits the impact of resource exhaustion attacks exploiting the vulnerable devalue.parse function.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.IR-03 mostly match
prevents

Resilience mechanisms such as rate limiting and load balancing directly constrain asymmetric resource use.

PR.IR-04 mostly match
prevents

Capacity planning and monitoring maintain availability headroom against amplification attacks.

DE.CM-01 partial match
prevents

Network monitoring detects amplification traffic patterns but does not itself limit asymmetric consumption.

DE.CM-09 partial match
prevents

Runtime resource monitoring can surface excessive consumption yet does not enforce authorization or work proofs.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

none

Stress-testing and demand-reduction tactics (e.g., bandwidth throttling) blunt amplification vectors that would otherwise let an attacker multiply resource consumption through a single request.

References