CVE-2021-36395

Moodle vulnerable to Uncontrolled Resource Consumption

7.5 HighFix available

In Moodle, the file repository's URL parsing required additional recursion handling to mitigate the risk of recursion denial of service.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: None
Integrity: None
Availability: High

Exploit likelihood

0.73%Up 0.7 points since Mar 7, 2023

What each source reports

NVD Score used 7.5

In Moodle, the file repository's URL parsing required additional recursion handling to mitigate the risk of recursion denial of service.

Record: CVE-2021-36395
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-400, CWE-674
Updated: 2026-11-02

CVE List 7.5

In Moodle, the file repository's URL parsing required additional recursion handling to mitigate the risk of recursion denial of service.

Record: CVE-2021-36395
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-400, CWE-674
Updated: 2026-11-02

EUVDEUVD-2023-0827 7.5

In Moodle, the file repository's URL parsing required additional recursion handling to mitigate the risk of recursion denial of service.

Record: EUVD-2023-0827
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

GitHub AdvisoriesGHSA-273w-7fxj-pcp6 7.5

Moodle vulnerable to Uncontrolled Resource Consumption

In Moodle, the file repository's URL parsing required additional recursion handling to mitigate the risk of recursion denial of service.

Record: GHSA-273w-7fxj-pcp6
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-400, CWE-674
Updated: 2026-11-02

OSV 7.5

In Moodle, the file repository's URL parsing required additional recursion handling to mitigate the risk of recursion denial of service.

Record: CVE-2021-36395
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVGHSA-273w-7fxj-pcp6 7.5

Moodle vulnerable to Uncontrolled Resource Consumption

In Moodle, the file repository's URL parsing required additional recursion handling to mitigate the risk of recursion denial of service.

Record: GHSA-273w-7fxj-pcp6
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-400, CWE-674
Updated: 2026-11-02

OSVUBUNTU-CVE-2021-36395 7.5

In Moodle, the file repository's URL parsing required additional recursion handling to mitigate the risk of recursion denial of service.

Record: UBUNTU-CVE-2021-36395
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVBIT-moodle-2021-36395 No score

In Moodle, the file repository's URL parsing required additional recursion handling to mitigate the risk of recursion denial of service.

Record: BIT-moodle-2021-36395
Updated: 2026-11-02

Affected products

moodle

Affected packages

Affected packages
Package	Affected	Fixed
`moodle/moodle` Packagist	3.11.0-beta up to 3.11.1	3.11.1
`moodle/moodle` Packagist	3.10.0-beta up to 3.10.5	3.10.5
`moodle/moodle` Packagist	before 3.9.8	3.9.8
`moodle` Bitnami	before 3.9.8, 3.10.0 up to 3.10.5, 3.11.0 up to 3.11.1	3.9.83.10.53.11.1
`moodle/moodle` Packagist	3.11.0-beta up to 3.11.1, plus listed versions v3.11.0v3.11.0-betav3.11.0-rc1v3.11.0-rc2	3.11.1
`moodle/moodle` Packagist	3.10.0-beta up to 3.10.5, plus listed versions v3.10.0v3.10.0-betav3.10.0-rc1v3.10.0-rc2v3.10.1v3.10.2v3.10.3v3.10.4	3.10.5
`moodle/moodle` Packagist	before 3.9.8, plus listed versions v2.3.10v2.3.11v2.3.4v2.3.5v2.3.6 Show 45 moreShow less v2.3.7v2.3.8v2.3.9v2.4.0v2.4.0-rc1v2.4.1v2.4.10v2.4.11v2.4.2v2.4.3v2.4.4v2.4.5v2.4.6v2.4.7v2.4.8v2.4.9v2.5.0v2.5.0-betav2.5.0-rc1v2.5.1v2.5.2v2.5.3v2.5.4v2.5.5v2.5.6v2.5.7v2.5.8v2.5.9v2.6.0v2.6.0-betav2.6.0-rc1v2.6.1v2.6.10v2.6.11v2.6.2v2.6.3v2.6.4v2.6.5v2.6.6v2.6.7v2.6.8v2.6.9v2.7.0v2.7.0-betav2.7.0-rc1	3.9.8
`moodle` Ubuntu:Pro:16.04:LTS	All versions, plus listed versions 2.7.9+dfsg-12.7.10+dfsg-12.7.11+dfsg-12.7.11+dfsg-22.7.12+dfsg-13.0.3+dfsg-0ubuntu13.0.3+dfsg-0ubuntu1+esm1	None known
`moodle` Ubuntu:Pro:18.04:LTS	All versions, plus listed versions 3.0.3+dfsg-0ubuntu13.0.3+dfsg-0ubuntu1+esm1	None known

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-36395 is a high vulnerability (CVSS 7.5) in Moodle, published March 6, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.73%, the 54th percentile. Fixed in moodle/moodle 3.11.1.

References

This page doesn't list everything

Left out here: 205 versions. The JSON record has them.