CVE-2026-22774 is a vulnerability categorized under CWE-405 (Asymmetric Resource Consumption) found in the sveltejs devalue library, a JavaScript utility designed to serialize complex values into strings when JSON.stringify is insufficient. The vulnerability exists in versions 5.3.0 through 5.6.1, where the devalue.parse function improperly handles certain inputs. Specifically, the function expects a typed array hydration input to be an ArrayBuffer but does not validate this assumption before creating the typed array. Maliciously crafted inputs can exploit this flaw to cause excessive CPU and memory consumption during parsing, leading to denial of service conditions. This is particularly dangerous in scenarios where devalue.parse processes untrusted external data, such as user inputs or API payloads. The vulnerability does not affect confidentiality or integrity but severely impacts availability by enabling resource exhaustion attacks. Exploitation requires no privileges or user interaction and can be triggered remotely if the affected parsing functionality is exposed. The vulnerability was publicly disclosed on January 15, 2026, with a CVSS v3.1 base score of 7.5 (high severity), reflecting its ease of exploitation and significant impact on availability. The issue was resolved in version 5.6.2 of the devalue library. No known exploits are currently reported in the wild, but the potential for denial of service attacks remains a concern for affected deployments.

For European organizations, the primary impact of CVE-2026-22774 is the risk of denial of service attacks against applications using vulnerable versions of the sveltejs devalue library. This can lead to service outages, degraded performance, and potential disruption of business-critical web applications or APIs that rely on devalue.parse to handle external input. Sectors such as finance, e-commerce, public services, and telecommunications, which often use modern JavaScript frameworks including Svelte, may face operational interruptions. The vulnerability does not compromise data confidentiality or integrity but can significantly affect availability, leading to loss of customer trust, regulatory scrutiny under GDPR for service disruptions, and financial losses. Since exploitation requires no authentication or user interaction, attackers can remotely trigger resource exhaustion with crafted payloads, increasing the attack surface. Organizations with automated input processing pipelines or public-facing APIs that utilize devalue.parse are particularly vulnerable. The absence of known exploits in the wild suggests a window of opportunity for proactive patching to prevent potential attacks.

European organizations should immediately upgrade the sveltejs devalue library to version 5.6.2 or later to remediate this vulnerability. If upgrading is not immediately feasible, implement input validation and sanitization to ensure that only expected data types are passed to devalue.parse, particularly verifying that inputs expected to be ArrayBuffers are validated before processing. Employ rate limiting and anomaly detection on endpoints that accept external input to mitigate potential resource exhaustion attempts. Monitor application performance metrics and logs for unusual CPU or memory spikes that could indicate exploitation attempts. Consider isolating or sandboxing components that use devalue.parse to limit the impact of potential DoS attacks. Additionally, conduct a thorough inventory of all applications and services using the affected library versions to prioritize patching efforts. Engage with development teams to review and harden input handling logic and incorporate security testing focused on resource consumption vulnerabilities. Finally, maintain up-to-date threat intelligence feeds to detect emerging exploit attempts targeting this vulnerability.