CVE-2021-30900: Apple iOS, iPadOS, and macOS Out-of-Bounds Write Vulnerability
- Is it exploited?
Yes. CISA added it to the Known Exploited Vulnerabilities catalog on 30 Mar 2023, 583 days after the CVE record was published.
- How likely is exploitation in the next 30 days?
- 5.2%
EPSS score, percentile 92.5 of all scored records
- How severe?
- 7.8 High
CVSS v3.1 base score, from CISA's enrichment of the record
- What should I do?
Required action (CISA), due 20 Apr 2023: Apply updates per vendor instructions.
The CVE record links no vendor advisory, patch or mitigation.
- Which versions are affected?
Affected: before 15.1; before 14.8
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
What to do
Required action, set by CISA
Apply updates per vendor instructions.
CISA due date for this action: 20 April 2023.
Advisories and patches
The CVE record links no vendor advisory, patch or mitigation.
Linked from CISA's catalog entry
- https://support.apple.com/en-us/HT21286
- https://support.apple.com/en-us/HT212868
- https://support.apple.com/kb/HT212872
- https://nvd.nist.gov/vuln/detail/CVE-2021-30900
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | before 15.1 |
| Status | Versions |
|---|---|
| Affected | before 14.8 |
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
About this vulnerability
Apple GPU drivers, included in iOS, iPadOS, and macOS, contain an out-of-bounds write vulnerability that may allow a malicious application to execute code with kernel privileges.
Summary: CISA's KEV catalog, as of 28 Oct 2026.
- CISA added CVE-2021-30900 to its Known Exploited Vulnerabilities (KEV) catalog on 30 Mar 2023.
- 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 20 Apr 2023.
- The CVE record was published on 24 Aug 2021, 583 days before it was added to KEV.
- The CVE record carries a CVSS v3.1 base score of 7.8 (High), taken from CISA's enrichment of the record.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 5.2% (percentile 92.5), 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 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026. About the data.
Description
An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 14.8.1 and iPadOS 14.8.1, iOS 15.1 and iPadOS 15.1. A malicious application may be able to execute arbitrary code with kernel privileges.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. 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 |
|---|---|
| 24 Aug 2021 | CVE record published |
| 30 Mar 2023 | Added to CISA KEV |
| 20 Apr 2023 | CISA due date for the required action |
| 21 Oct 2025 | CVE record last updated |
References
More exploited Apple vulnerabilities
- CVE-2026-86950: Apple Multiple Products Out-of-Bounds Write Vulnerability
- CVE-2026-65400: Apple macOS Improper Authentication Vulnerability
- CVE-2025-31277: Apple Multiple Products Buffer Overflow Vulnerability
- CVE-2025-43510: Apple Multiple Products Improper Locking Vulnerability
- CVE-2025-43520: Apple Multiple Products Classic Buffer Overflow Vulnerability
- CVE-2021-30952: Apple Multiple Products Integer Overflow or Wraparound Vulnerability