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Fencer Intel
medium 5.4

CVE-2020-8294 json

A missing link validation in Nextcloud Server before 20.0.2, 19.0.5, 18.0.11 allows execution of a stored XSS attack using Internet Explore…

published 5y ago modified 4mo ago also EUVD-2020-29162

cvss
5.4
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 61%
public exploits
0
none known

Summary

A missing link validation in Nextcloud Server before 20.0.2, 19.0.5, 18.0.11 allows execution of a stored XSS attack using Internet Explorer when saving a 'javascript:' URL in markdown format.

Patch / fix

  • nextcloud nextcloud_server 18.0.11, 19.0.5, 20.0.2
  • nextcloud Package Hub 15 SP3, Package Hub 15 SP2, Package Hub 15 SP1 +3 more 20.0.11-bp153.2.3.1
  • nextcloud Package Hub 15 SP2 20.0.7-bp152.2.6.1
  • nextcloud openSUSE Leap 15.2 20.0.7-lp152.3.6.1

opensuse advisories openSUSE-SU-2021:1068-1openSUSE-SU-2021:0274-1openSUSE-SU-2021:0262-1

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Exploit prediction

0.94% chance of exploitation in the next 30 days, higher than 61% of all scored CVEs (FIRST EPSS, 2026-11-09).

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

Affected products

  • n/a Nextcloud Server

Classification

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

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.