CVE•Published 2026-04-09•Modified 2026-04-14•0 articles on news•6 live references•NVD data

CVE-2026-35041Nearform · Fast-jwt

Vulnerability data via NVD (ingested)

CVSS v3.1

4.2

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:H

EPSS percentile

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Weaknesses (CWE)

CWE-1333Inefficient Regular Expression Complexity

Description

fast-jwt provides fast JSON Web Token (JWT) implementation. From 5.0.0 to 6.2.0, a denial-of-service condition exists in fast-jwt when the allowedAud verification option is configured using a regular expression. Because the aud claim is attacker-controlled and the library evaluates it against the supplied RegExp, a crafted JWT can trigger catastrophic backtracking in the JavaScript regex engine, resulting in significant CPU consumption during verification. This vulnerability is fixed in 6.2.1.

Timeline

Published 2026-04-09

Modified 2026-04-14

External references

NVD MITRE Exploit-DB GitHub PoC Sploitus VulnCheck

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).

Shodan · vuln tag0 hosts

vuln:CVE-2026-35041

Hosts Shodan has explicitly fingerprinted as vulnerable.

Shodan · product

product:"Nearform Fast-jwt"

All exposed Nearform Fast-jwt instances — cross-reference with the CVE's affected-version range.

Shodan · banner/body mention

http.html:"Fast-jwt"

HTTP body or banner mentions "Fast-jwt" — catches deploys Shodan didn't identify as a product.

More intel sources (5)

Shodan report

vuln:CVE-2026-35041