NextScripts: Social Networks Auto-Poster <= 4.3.20 Reflected Cross-Site Scripting

published 2021-11-01 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-24809

cvss: 6.1; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.9%; EPSS 0.9% chance of exploitation in 30 days, percentile 59%
public exploits: 0; none known

The NextScripts: Social Networks Auto-Poster <= 4.3.20 WordPress plugin is vulnerable to Reflected Cross-Site Scripting via the $_REQUEST['page'] parameter which is echoed out on inc/nxs_class_snap.php by supplying the appropriate value 'nxssnap-post' to load the page in $_GET['page'] along with malicious JavaScript in $_POST['page'].

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 19 mo ago (2025-03-31)

Exploit prediction

0.87% chance of exploitation in the next 30 days, higher than 59% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

wordfence.com https://www.wordfence.com/blog/2021/10/xss-vulnerability-in-nextscripts-social-networks-auto-poster-plugin-impacts-100000-sites/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	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

Affected products

NextScripts NextScripts: Social Networks Auto-Poster

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

Technology feeds

WordPress rss critical rss

References

wordfence.com /blog/2021/10/xss-vulnerability-in-nextscripts-social-networks-auto-poster-plugin-impacts-100000-sites/
exploit, third-party-advisory

Sources

CVE List CVE-2021-38356
NVD CVE-2021-38356

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