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Vulnerabilities

Vulnerability · CVE-2021-20280

Text-based feedback answers required additional sanitizing to prevent stored XSS and blind SSRF risks in moodle before 3.10.2, 3.9.5, 3.8.8, 3.5.17.

Published Mar 15, 2021 · catalog updated Jun 17, 2026 · Text-based feedback answers required

Last checked Nov 7, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2021-20280. EPSS is 1.27%. Act only if a listed version of Text-based feedback answers required is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Text-based feedback answers required).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
Medium5.4
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
1.27%
Remediation
Version ranges on file
Affected products
cpe fedoraproject/fedora · cpe moodle/moodle

Text-based feedback answers required additional sanitizing to prevent stored XSS and blind SSRF risks in moodle before 3.10.2, 3.9.5, 3.8.8, 3.5.17.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe fedoraproject/fedora32
  • cpe fedoraproject/fedora33
  • cpe moodle/moodle< 3.10.2
  • cpe moodle/moodle< 3.5.17
  • cpe moodle/moodle< 3.8.8
  • cpe moodle/moodle< 3.9.5

How to fix CVE-2021-20280

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2021-20280. EPSS is 1.27%. Act only if a listed version of Text-based feedback answers required is installed.

Which versions are affected?

Compare what you have installed with 32, 33, < 3.10.2, < 3.5.17, < 3.8.8, < 3.9.5. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-79: Cross-site Scripting (XSS). EPSS 1.27%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Moodle security

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Mar 15, 2021 · Monitored products — high

    Detected

    Text-based feedback answers required additional sanitizing to prevent stored XSS and blind SSRF risks in moodle before 3.10.2, 3.9.5, 3.8.8, 3.5.17.

  2. Jun 17, 2026 · Monitored products — high

    Updated

    Text-based feedback answers required additional sanitizing to prevent stored XSS and blind SSRF risks in moodle before 3.10.2, 3.9.5, 3.8.8, 3.5.17.

Sources

  • CVE.orgVulnerability recordCVE-2021-20280

    Official CVE identifier

    cve.org
  • Monitored products — highVendor advisoryCVE-2021-20280

    Text-based feedback answers required additional sanitizing to prevent stored XSS and blind SSRF risks in moodle before 3.10.2, 3.9.5, 3.8.8, 3.5.17.

    nvd.nist.gov
  • Packet Storm SecurityCited referencehttp://packetstormsecurity.com/files/164817/Moodle-Cross-Site-Scripting-Server-Side-Request-Forgery.html

    Packet Storm link already published on the finding.

    packetstormsecurity.com

References

Freshness

Last verified in this catalog Nov 7, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • Packet Storm SecurityNov 7, 2026
  • CVE.orgNov 4, 2026
  • Monitored products — highNov 4, 2026