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CVE-2021-36396

High (7.5)—PoC
Patch with priorityPublic exploit code is available (Proof of concept on GitHub (unverified)). No confirmed active exploitation.
Vendor advisory· moodle.org/mod/forum/discuss.php
Severity7.5High · CVSS 3.1
Exploitation probability1.43 %higher than 73% of CVEs · score from Nov 8, 2026
Active exploitationNonot in the CISA catalog · checked Nov 8, 05:00 PM
Public exploitAvailableProof of concept on GitHub (unverified)

In Moodle, insufficient redirect handling made it possible to blindly bypass cURL blocked hosts/allowed ports restrictions, resulting in a blind SSRF risk.

Timeline

Built from our own data: NVD, CISA KEV, FIRST EPSS, public exploits, specialised media and Orbitaley coverage.

  1. CVE record published in NVD
  2. Record last modified in NVD
  3. First public exploit

Public exploits

Exploit code or detection templates are publicly available. This is not the same as confirmed active exploitation (KEV), but it raises the risk: patch with priority.

⚠️ GitHub proofs of concept are not verified: some are fake or contain malware. Never run them outside an isolated lab.

Affected technologies (1)

Moodle — Moodle

NVD record

NVD status
Modified
Published
Mar 6, 2023
Last modified
Jun 17, 2026
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Weakness (CWE)
CWE-918

References

Raw JSON (NVD)

Show
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  "id": "CVE-2021-36396",
  "cveTags": [],
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