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Vulnerability details: VCID-jcq6-btgz-fkf6
Vulnerability ID VCID-jcq6-btgz-fkf6
Aliases CVE-2021-20183
GHSA-xhfx-rm8q-c3xv
Summary Cross-site Scripting It was found in Moodle that some search inputs were vulnerable to reflected XSS due to insufficient escaping of search queries.
Status Published
Exploitability None
Weighted Severity None
Risk None
Affected and Fixed Packages Package Details
Weaknesses (3)
CWE-1035 OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CWE-937 OWASP Top Ten 2013 Category A9 - Using Components with Known Vulnerabilities
System Score Found at
epss 0.00455 https://api.first.org/data/v1/epss?cve=CVE-2021-20183
cvssv3.1 5.4 https://github.com/moodle/moodle/commit/dc9de7b0d487b73c23c221dc0b8b6e01654921f3
generic_textual MODERATE https://github.com/moodle/moodle/commit/dc9de7b0d487b73c23c221dc0b8b6e01654921f3
cvssv3.1 5.4 https://moodle.org/mod/forum/discuss.php?d=417166
generic_textual MODERATE https://moodle.org/mod/forum/discuss.php?d=417166
cvssv3.1 5.4 https://nvd.nist.gov/vuln/detail/CVE-2021-20183
generic_textual MODERATE https://nvd.nist.gov/vuln/detail/CVE-2021-20183
Reference id Reference type URL
https://api.first.org/data/v1/epss?cve=CVE-2021-20183
https://github.com/moodle/moodle/commit/dc9de7b0d487b73c23c221dc0b8b6e01654921f3
https://moodle.org/mod/forum/discuss.php?d=417166
CVE-2021-20183 https://nvd.nist.gov/vuln/detail/CVE-2021-20183
No exploits are available.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N Found at https://github.com/moodle/moodle/commit/dc9de7b0d487b73c23c221dc0b8b6e01654921f3
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N Found at https://moodle.org/mod/forum/discuss.php?d=417166
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N Found at https://nvd.nist.gov/vuln/detail/CVE-2021-20183
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Exploit Prediction Scoring System (EPSS)
Percentile 0.64171
EPSS Score 0.00455
Published At June 4, 2026, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2026-06-04T16:20:46.035743+00:00 GitLab Importer Import https://gitlab.com/gitlab-org/advisories-community/-/blob/main/packagist/moodle/moodle/CVE-2021-20183.yml 38.6.0