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Fencer Vulns
medium 5.4

CVE-2021-3355 json

A stored-self XSS exists in LightCMS v1.3.4, allowing an attacker to execute HTML or JavaScript code in a vulnerable Title field to /admin/…

published 2021-02-24 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-26686

cvss
5.4
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
7.2%
EPSS 7.2% chance of exploitation in 30 days, percentile 94%
public exploits
1
Exploit-DB

Summary

A stored-self XSS exists in LightCMS v1.3.4, allowing an attacker to execute HTML or JavaScript code in a vulnerable Title field to /admin/SensitiveWords.

Timeline

  1. Published
  2. First public exploit (EDB-49598)

Exploit prediction

7.25% chance of exploitation in the next 30 days, higher than 94% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • EDB-49598 LightCMS 1.3.4 - 'exclusive' Stored XSS webapps, 2021-02-26
  • github.com https://github.com/eddy8/LightCMS/issues/18 referenced PoC, tagged "exploit" by a source, unverified
  • packetstormsecurity.com http://packetstormsecurity.com/files/161562/LightCMS-1.3.4-Cross-Site-Scripting.html referenced PoC, tagged "exploit" by a source, unverified
  • gist.github.com https://gist.github.com/Peithon/1c628ded0c4fc96c6331c3cce1d0c69b referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
NVD 2.0 3.5 AV:N/AC:M/Au:S/C:N/I:P/A:N

Classification

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

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.