EUVD-2026-40267Severity by source
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/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:N/AU:Y/R:U/V:D/RE:M/U:Amber
Network-reachable decode() input path, no auth or interaction required; scope unchanged, only availability impacted via event-loop blocking.
Primary rating from Vendor (seal).
CVSS VectorVendor: seal
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/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:N/AU:Y/R:U/V:D/RE:M/U:Amber
Lifecycle Timeline
2DescriptionCVE.org
decode-uri-component through 0.4.1 is vulnerable to denial of service. The decode() function splits input on '%' producing N tokens and calls decodeComponents(), exhibiting super-linear parsing time: 200 '%ab' tokens takes approximately 0.7s, 700 tokens approximately 6s, and 1400 tokens approximately 33s. An attacker can cause significant CPU consumption and event-loop blocking via crafted input.
AnalysisAI
Super-linear algorithmic complexity in the decode-uri-component npm package (versions through 0.4.1) allows unauthenticated network attackers to cause severe CPU exhaustion and block the Node.js event loop by submitting crafted strings with large numbers of percent-encoded tokens. The decode() function splits input on '%' and iteratively invokes decodeComponents() in a pattern producing quadratic or worse time growth - 1,400 '%ab' tokens consume approximately 33 seconds of CPU, rendering single-threaded JavaScript runtimes effectively unresponsive. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | The vulnerable application must route attacker-controlled string input to decode-uri-component's decode() function specifically - the native decodeURIComponent() is not affected. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 4.0 base vector (AV:N/AC:L/AT:N/PR:N/UI:N/VA:H) is consistent with the description: exploitation requires no authentication, no special attack conditions, and no user interaction, while producing high availability impact. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An attacker identifies a web endpoint that passes user-supplied URL query parameters or path components through decode-uri-component's decode() function. The attacker submits an HTTP request containing a query string composed of approximately 1,400 repetitions of '%ab', triggering roughly 33 seconds of CPU blocking on the target's Node.js event loop per request. … |
| Remediation | Upgrade decode-uri-component to a version newer than 0.4.1, verifying the current latest release at https://www.npmjs.com/package/decode-uri-component before updating, as the upstream fix commit (fa479dafeede7bedf04e5c89aa78f2a78c664005) is confirmed but the corresponding npm release version is not independently verified from provided data. … Detailed patch versions, workarounds, and compensating controls in full report. |
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More in Decode Uri Component
View allSame weakness CWE-400 – Uncontrolled Resource Consumption
View allSame technique Denial Of Service
View allShare
External POC / Exploit Code
Leaving vuln.today