CVE-2021-38661
HEVC Video Extensions Remote Code Execution Vulnerability
HEVC Video Extensions Remote Code Execution Vulnerability
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
HEVC Video Extensions Remote Code Execution Vulnerability
HEVC Video Extensions Remote Code Execution Vulnerability
- Record
CVE-2021-38661- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C - Updated
- 2026-11-02
EUVDEUVD-2021-25100
HEVC Video Extensions Remote Code Execution Vulnerability
- Record
EUVD-2021-25100- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-mcj5-4xrx-fgf3
HEVC Video Extensions Remote Code Execution Vulnerability
HEVC Video Extensions Remote Code Execution Vulnerability
- Record
GHSA-mcj5-4xrx-fgf3- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
NVD
HEVC Video Extensions Remote Code Execution Vulnerability
- Record
CVE-2021-38661- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - CVSS 2.0
- 6.8 Medium
AV:N/AC:M/Au:N/C:P/I:P/A:P - Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-38661 is a high vulnerability (CVSS 7.8) in Microsoft Hevc Video Extensions, published September 15, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.29%, the 83rd percentile. No source names a fixed version.