Elysia: Inefficient Algorithmic Complexity and Interpretation Conflict

published 2026-07-08 4 mo ago modified 2026-10-25 15 d ago also EUVD-2026-42394 , GHSA-9643-4qgh-g8mx

cvss: 7.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.6%; EPSS 0.6% chance of exploitation in 30 days, percentile 50%
public exploits: 0; none known

Elysia is a Typescript framework for request validation, type inference, OpenAPI documentation, and client-server communication. Prior to 1.4.29, Elysia uses getAll in form data normalization for multipart/form-data endpoints, causing the amount of work to grow quadratically with the number of unique key-value pairs and allowing CPU exhaustion. This issue is fixed in version 1.4.29.

Patch / fix

fixed in 2 links 2

npm elysia 1.4.29
elysiajs elysia 1.4.29

github.com/elysiajs/elysia@8358ff9 commit
github.com/elysiajs/elysia/releases/tag/1.4.29 release

CISA SSVC

Exploitation: none
Automatable: yes
Technical impact: partial
Assessed: 4 mo ago (2026-07-10)

Exploit prediction

0.63% chance of exploitation in the next 30 days, higher than 50% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
GitHub	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem	package	affected	fixed in
npm	elysia	<1.4.29	1.4.29

Affected products

elysiajs elysia

Classification

Weakness

CWE-407 Inefficient Algorithmic Complexity
CWE-436 Interpretation Conflict

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary