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Fencer Intel
medium 4.8

CVE-2021-24516 json

PlanSo Forms <= 2.6.3 - Authenticated Stored Cross-Site Scripting

published 5y ago modified 4mo ago also EUVD-2021-11428

cvss
4.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 50%
public exploits
0
none known

Summary

The PlanSo Forms WordPress plugin through 2.6.3 does not escape the title of its Form before outputting it in attributes, allowing high privilege users such as admin to set XSS payload in it, even when the unfiltered_html is disallowed, leading to an Authenticated Stored Cross-Site Scripting issue.

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Exploit prediction

0.64% chance of exploitation in the next 30 days, higher than 50% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • wpscan.com https://wpscan.com/vulnerability/88d70e35-4c22-4bc7-b1a5-24068d55257c referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 4.8 CVSS:3.1/AV:N/AC:L/PR:H/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

Affected products

  • Unknown PlanSo Forms

Classification

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

References

Sources

Fencer Intel 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.