CVE-2021-36539

Public Exploit

Description

Instructure Canvas LMS didn't properly deny access to locked/unpublished files when the unprivileged user access the DocViewer based file preview URL (canvadoc_session_url).

Category

6.5
CVSS
Severity: Medium
CVSS 3.1 •
EPSS 0.23%
Third-Party Advisory github.com Third-Party Advisory github.com
Affected: n/a n/a
Published at:
Updated at:

References

Link Tags
https://github.com/instructure/canvas-lms/issues/1905 third party advisory exploit
https://github.com/gaukas/instructure-canvas-file-oracle third party advisory exploit

Frequently Asked Questions

What is the severity of CVE-2021-36539?
CVE-2021-36539 has been scored as a medium severity vulnerability.
How to fix CVE-2021-36539?
To fix CVE-2021-36539, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-36539 being actively exploited in the wild?
It is possible that CVE-2021-36539 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.
© 2025 Under My Watch. All Rights Reserved.