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Vulnerability record · CVE-2021-25810 · published 29 April 2021

CVE-2021-25810: Mercusys mercury x18g firmware cross-site scripting vulnerability

Mercusys · Mercury X18g Firmware

Cross site Scripting (XSS) vulnerability in MERCUSYS Mercury X18G 1.0.5 devices, via crafted values to the 'src_dport_start', 'src_dport_end', and 'dest_port' parameters.

6.1 CVSS 3.1 Medium EPSS 1.1% · top 35.4% CWE-79 · Cross-site scripting
6.1CVSS 3.1 base score, v2 4.3
1.1%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
6References, 2 tagged exploit
17 Jun 2026Last modified by NVD

Description

Cross site Scripting (XSS) vulnerability in MERCUSYS Mercury X18G 1.0.5 devices, via crafted values to the 'src_dport_start', 'src_dport_end', and 'dest_port' parameters.

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

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/pokerfacett/MY_REQUEST/blob/master/Mercury%20Router%20X18g%20v1.0.5%20Stored%20XSS.md ExploitThird Party Advisory
https://www.mercurycom.com.cn/product-521-1.html Broken Link
https://www.mercusys.com/en/ Vendor Advisory
https://github.com/pokerfacett/MY_REQUEST/blob/master/Mercury%20Router%20X18g%20v1.0.5%20Stored%20XSS.md ExploitThird Party Advisory
https://www.mercurycom.com.cn/product-521-1.html Broken Link
https://www.mercusys.com/en/ Vendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2021-25810), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.