CVE-2021-36747Public exploitNetwork attack vector

Authenticated script execution via unsanitized assignment feedback

Published Jul 20, 2021 · Updated Aug 4, 2024

Stored XSS in Blackboard Learn 9.1 and earlier allows remote authenticated users to execute scripts via crafted Feedback to Learner text. The grading tool converts feedback text to HTML and stores script tags without neutralization, then a learner's Grades page executes the script in the browser. Instructor or grader access is required to submit the payload, and a learner must view the stored feedback; execution occurs in that learner's browser context.

CVSS severity5.4
Medium
EPSS probability0.62%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Blackboard Learn 9.1 and earlier allows remote authenticated users to execute scripts via crafted Feedback to Learner text. The grading tool converts feedback text to HTML and stores script tags without neutralization, then a learner's Grades page executes the script in the browser. Instructor or grader access is required to submit the payload, and a learner must view the stored feedback; execution occurs in that learner's browser context.

The record

CVE
CVE-2021-36747
Published
Jul 20, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 20, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.4NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
3.5NVDAV:N/AC:M/Au:S/C:N/I:P/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007Command and Scripting Interpreter: JavaScript

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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