Formstone Vulnerable to Reflected XSS

published 2021-01-07 5 y ago modified 2026-06-17 4 mo ago also GHSA-wc29-h54q-q8qx , EUVD-2022-5546

cvss: 6.1; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.3%; EPSS 1.3% chance of exploitation in 30 days, percentile 70%
public exploits: 0; none known

Formstone <=1.4.16 is vulnerable to a Reflected Cross-Site Scripting (XSS) vulnerability caused by improper validation of user supplied input in the upload-target.php and upload-chunked.php files. A remote attacker could exploit this vulnerability using a specially crafted URL to execute a script in a victim's Web browser within the security context of the hosting Web site once the URL is clicked or visited. An attacker could use this vulnerability to steal the victim's cookie-based authentication credentials, force malware execution, user redirection and others.

Patch / fix

fixed in 1 links 1

npm formstone 1.4.17

github.com/Formstone/Formstone@b067f31 commit

Exploit prediction

1.28% chance of exploitation in the next 30 days, higher than 70% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.1	6.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
NVD	2.0	4.3	AV:N/AC:M/Au:N/C:N/I:P/A:N
GitHub	3.1	6.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Affected packages

ecosystem	package	affected	fixed in
npm	formstone	<1.4.17	1.4.17

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

References

github.com /Formstone/Formstone/commit/b067f31f5f6a0acd3ade4fd6dccae6e3633caa02
web
github.com /Formstone/Formstone/issues/286
web, third-party-advisory
nvd.nist.gov /vuln/detail/CVE-2020-26768
advisory

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