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Fencer Vulns
medium 6.1

CVE-2021-24495 json

Marmoset Viewer < 1.9.3 - Reflected Cross Site Scripting

published 2021-08-09 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-11407

cvss
6.1
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
3.3%
EPSS 3.3% chance of exploitation in 30 days, percentile 88%
public exploits
0
none known, plus a Nuclei check

Summary

The Marmoset Viewer WordPress plugin before 1.9.3 does not property sanitize, validate or escape the 'id' parameter before outputting back in the page, leading to a reflected Cross-Site Scripting issue.

Patch / fix

  • marmoset marmoset_viewer 1.9.3

Exploit prediction

3.34% chance of exploitation in the next 30 days, higher than 88% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • Nuclei template Wordpress Marmoset Viewer <1.9.3 - Cross-Site Scripting nuclei detection template
  • wpscan.com https://wpscan.com/vulnerability/d11b79a3-f762-49ab-b7c8-3174624d7638 referenced PoC, tagged "exploit" by a source, unverified
  • johnjhacking.com https://johnjhacking.com/blog/cve-2021-24495-improper-neutralization-of-input-during-web-page-generation-on-id-parameter-in-wordpress-marmoset-viewer-plugin-versions-1.9.3-leads-to-reflected-cross-site-scripting/ referenced PoC, tagged "exploit" by a source, unverified

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

Affected products

  • Unknown Marmoset Viewer

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation
Technology feeds

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.