CVE-2021-0920: Android Kernel Race Condition Vulnerability
- Is it exploited?
Yes. CISA added it to the Known Exploited Vulnerabilities catalog on , 159 days after the CVE record was published.
- How likely is exploitation in the next 30 days?
- 0.9%
EPSS score, percentile 58.6 of all scored records
- How severe?
- 6.4 Medium
CVSS v3.1 base score, from CISA's enrichment of the record
- What should I do?
CISA deadline . Apply updates per vendor instructions.
The CVE record links no vendor advisory, patch or mitigation.
- Which versions are affected?
Affected
- Android kernel
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of ; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of ; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.
What to do
Required action, set by CISA
Apply updates per vendor instructions.
CISA due date for this action: .
Advisories and patches
The CVE record links no vendor advisory, patch or mitigation.
Linked from CISA's catalog entry
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | Android kernel |
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.
About this vulnerability
Android kernel contains a race condition, which allows for a use-after-free vulnerability. Exploitation can allow for privilege escalation.
Summary: CISA's KEV catalog, as of .
- CISA added CVE-2021-0920 to its Known Exploited Vulnerabilities (KEV) catalog on 23 May 2022.
- CISA's ransomware flag for this entry is "Unknown": no evidence of ransomware use in the catalog, which is not proof of none.
- The due date CISA sets for the required action is 13 Jun 2022.
- The CVE record was published on 15 Dec 2021, 159 days before it was added to KEV.
- The CVE record carries a CVSS v3.1 base score of 6.4 (Medium), taken from CISA's enrichment of the record.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.9% (percentile 58.6), as of 28 Oct 2026.
- CISA's SSVC assessment in the CVE record: exploitation active, automatable no, technical impact total.
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of ; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of ; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of . About the data.
Description
In unix_scm_to_skb of af_unix.c, there is a possible use after free bug due to a race condition. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android kernelAndroid ID: A-196926917References: Upstream kernel
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.
Weakness
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record and the KEV entry.
Timeline
| Date | Event |
|---|---|
| CVE record published | |
| Added to CISA KEV | |
| CISA due date for the required action | |
| CVE record last updated |
References
More exploited Android vulnerabilities
- CVE-2025-48595: Android Framework Integer Overflow Vulnerability
- CVE-2025-48572: Android Framework Privilege Escalation Vulnerability
- CVE-2025-48633: Android Framework Information Disclosure Vulnerability
- CVE-2025-48543: Android Runtime Use-After-Free Vulnerability
- CVE-2024-43093: Android Framework Privilege Escalation Vulnerability
- CVE-2024-36971: Android Kernel Remote Code Execution Vulnerability