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Fencer Vulns
medium 6.1

CVE-2021-20663 json

Cross-site scripting vulnerability in in Role authority setting screen of Movable Type 7 r.4705 and earlier (Movable Type 7 Series), Movabl…

published 2021-03-05 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-8081

cvss
6.1
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.8%
EPSS 0.8% chance of exploitation in 30 days, percentile 58%
public exploits
0
none known

Summary

Cross-site scripting vulnerability in in Role authority setting screen of Movable Type 7 r.4705 and earlier (Movable Type 7 Series), Movable Type Advanced 7 r.4705 and earlier (Movable Type Advanced 7 Series), Movable Type 6.7.5 and earlier (Movable Type 6.7 Series), Movable Type Premium 1.39 and earlier, and Movable Type Premium Advanced 1.39 and earlier allows remote attackers to inject an arbitrary script via unspecified vectors.

Exploit prediction

0.84% chance of exploitation in the next 30 days, higher than 58% of all scored CVEs (FIRST EPSS, 2026-11-08).

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

  • Six Apart Ltd. Movable Type

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.