FUXA has JWT Authentication Bypass via HTTP Referer header spoofing

published 2026-02-24 8 mo ago modified 2026-06-17 4 mo ago also GHSA-4r4r-4jp4-wwf9 , EUVD-2025-208092

cvss: 9.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 6.0%; EPSS 6.0% chance of exploitation in 30 days, percentile 93%
public exploits: 1; Exploit-DB

FUXA 1.2.8 and prior contains an Authentication Bypass vulnerability leading to Remote Code Execution (RCE). The vulnerability exists in the server/api/jwt-helper.js middleware, which improperly trusts the HTTP "Referer" header to validate internal requests. A remote unauthenticated attacker can bypass JWT authentication by spoofing the Referer header to match the server's host. Successful exploitation allows the attacker to access the protected /api/runscript endpoint and execute arbitrary Node.js code on the server.

Timeline

2026-02-24 Published
2026-04-30 First public exploit (EDB-52544)

CISA SSVC

Exploitation: Proof of concept is public
Automatable: yes
Technical impact: total
Assessed: 8 mo ago (2026-02-25)

Exploit prediction

6.02% chance of exploitation in the next 30 days, higher than 93% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

EDB-52544 FUXA 1.2.8 - Authentication Bypass + RCE Exploit webapps, 2026-04-30
gist.github.com https://gist.github.com/lihy10/8cb2dd65ebf1385f12a7e00e25a50d40 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
GitHub	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem	package	affected	fixed in
npm	@frangoteam/fuxa	<=1.2.8	no fix listed

Classification

Weakness

CWE-288 Authentication Bypass Using an Alternate Path or Channel

References

gist.github.com /lihy10/8cb2dd65ebf1385f12a7e00e25a50d40
web, exploit, third-party-advisory
github.com /frangoteam/FUXA/blob/master/server/api/jwt-helper.js
web, product
nvd.nist.gov /vuln/detail/CVE-2025-69985
advisory
github.com /frangoteam/FUXA
package

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.

Summary