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 0.0058 45th percentile
Risk Priority 58 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

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 Network Denial of Service (T1498); ranked at the 45th 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 SC-5 (Denial-of-service Protection) and SC-6 (Resource Availability) — 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 Techniques

T1498 Network Denial of Service Impact
Adversaries may perform Network Denial of Service (DoS) attacks to degrade or block the availability of targeted resources to users.
T1499.002 Service Exhaustion Flood Impact
Adversaries may target the different network services provided by systems to conduct a denial of service (DoS).
T1499.003 Application Exhaustion Flood Impact
Adversaries may target resource intensive features of applications to cause a denial of service (DoS), denying availability to those applications.
T1498.002 Reflection Amplification Impact
Adversaries may attempt to cause a denial of service (DoS) by reflecting a high-volume of network traffic to a target.
T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
T1499.001 OS Exhaustion Flood Impact
Adversaries may launch a denial of service (DoS) attack targeting an endpoint's operating system (OS).
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-22775Same product: Svelte Devalue
CVE-2026-42570Same product: Svelte Devalue
CVE-2026-30226Same product: Svelte Devalue
CVE-2026-40073Same vendor: Svelte
CVE-2026-22803Same vendor: Svelte
CVE-2025-42876Shared CWE-405
CVE-2025-66506Shared CWE-405
CVE-2026-0485Shared CWE-405
CVE-2024-34702Shared 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)

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Detect
Catch it (NIST detect / respond)

—

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

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Mitigating Controls (NIST 800-53 r5) AI

SC-5 directly requires mechanisms to limit the effects of asymmetric resource exhaustion attacks such as amplification DoS.

SC-6 enforces resource quotas and priority allocation that reduce the impact of unauthenticated or low-effort resource requests.

Least-functionality disables unnecessary services or features that could be leveraged for amplification.

SC-7 boundary controls can filter or rate-limit traffic patterns that enable amplification without equivalent client work.

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.

mitigates

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.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (2 rules)
  • V-248553 OL 8 must be configured so that all network connections associated with SSH traffic are terminated after 10 minutes of becoming unresponsive. prevents CWE-405
  • V-248552 OL 8 must be configured so that all network connections associated with SSH traffic terminate after becoming unresponsive. prevents CWE-405
Oracle Linux 9 (2 rules)
  • V-271709 OL 9 must be configured so that all network connections associated with SSH traffic terminate after becoming unresponsive. prevents CWE-405
  • V-271710 OL 9 must be configured so that all network connections associated with SSH traffic are terminated after 10 minutes of becoming unresponsive. prevents CWE-405
RHEL 8 (2 rules)
  • V-230244 RHEL 8 must be configured so that all network connections associated with SSH traffic terminate after becoming unresponsive. prevents CWE-405
  • V-244525 RHEL 8 must be configured so that all network connections associated with SSH traffic are terminated after 10 minutes of becoming unresponsive. prevents CWE-405

References