CVE-2021-1861
An issue existed in determining cache occupancy. The issue was addressed through improved logic....
An issue existed in determining cache occupancy. The issue was addressed through improved logic. This issue is fixed in macOS Big Sur 11.3. A malicious website may be able to track users by setting state in a cache.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
An issue existed in determining cache occupancy. The issue was addressed through improved logic. This issue is fixed in macOS Big Sur 11.3. A malicious website may be able to track users by setting state in a cache.
- Record
CVE-2021-1861- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N - CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:P/I:N/A:N - Updated
- 2026-11-02
CVE ListNo score
An issue existed in determining cache occupancy. The issue was addressed through improved logic. This issue is fixed in macOS Big Sur 11.3. A malicious website may be able to track users by setting state in a cache.
- Record
CVE-2021-1861- Updated
- 2026-11-02
EUVDEUVD-2021-7325No score
An issue existed in determining cache occupancy. The issue was addressed through improved logic. This issue is fixed in macOS Big Sur 11.3. A malicious website may be able to track users by setting state in a cache.
- Record
EUVD-2021-7325- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-mwpq-gg3q-w4qr
An issue existed in determining cache occupancy. The issue was addressed through improved logic....
An issue existed in determining cache occupancy. The issue was addressed through improved logic. This issue is fixed in macOS Big Sur 11.3. A malicious website may be able to track users by setting state in a cache.
- Record
GHSA-mwpq-gg3q-w4qr- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N - Weakness
- CWE-668
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | ||
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-1861 is a medium vulnerability (CVSS 4.3) in Apple Macos, published September 8, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.87%, the 59th percentile. No source names a fixed version.