express-xss-sanitizer has an unbounded recursion depth

published 2025-09-14 13 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-29138 , GHSA-hvq2-wf92-j4f3

cvss: 5.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 39%
public exploits: 0; none known

The express-xss-sanitizer (aka Express XSS Sanitizer) package through 2.0.0 for Node.js has an unbounded recursion depth in sanitize in lib/sanitize.js for a JSON request body.

Patch / fix

fixed in 2 links 2

npm express-xss-sanitizer 2.0.1
express_xss_sanitizer_project express_xss_sanitizer 2.0.1

github.com/AhmedAdelFahim/express-xss-sanitizer@62d6542 commit
github.com/AhmedAdelFahim/express-xss-sanitizer#23 pull request

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 13 mo ago (2025-09-15)

Exploit prediction

0.45% chance of exploitation in the next 30 days, higher than 39% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	5.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Affected packages

ecosystem	package	affected	fixed in
npm	express-xss-sanitizer	<2.0.1	2.0.1

Affected products

Express XSS Sanitizer project Express XSS Sanitizer

Classification

Weakness

CWE-674 Uncontrolled Recursion

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