CVE-2021-30952: Apple Multiple Products Integer Overflow or Wraparound Vulnerability
- Is it exploited?
Yes. CISA added it to the Known Exploited Vulnerabilities catalog on , 1,654 days after the CVE record was published.
- How likely is exploitation in the next 30 days?
- 7%
EPSS score, percentile 94.1 of all scored records
- How severe?
- 8.8 High
CVSS v3.1 base score, from CISA's enrichment of the record
- What should I do?
CISA deadline . Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- Which versions are affected?
Affected
- before 8.3
- before 15.2
- before 12.1
- before 15.2
- before 15.2
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 mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
CISA due date for this action: .
Advisories and patches
Linked from CISA's catalog entry
- https://support.apple.com/en-us/HT212975
- https://support.apple.com/en-us/HT212976
- https://support.apple.com/en-us/HT212978
- https://support.apple.com/en-us/HT212980
- https://support.apple.com/en-us/HT212982
- https://nvd.nist.gov/vuln/detail/CVE-2021-30952
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | before 8.3 |
| Status | Versions |
|---|---|
| Affected | before 15.2 |
| Status | Versions |
|---|---|
| Affected | before 12.1 |
| Status | Versions |
|---|---|
| Affected | before 15.2 |
| Status | Versions |
|---|---|
| Affected | before 15.2 |
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.
About this vulnerability
Apple tvOS, macOS, Safari, iPadOS and watchOS contain an integer overflow or wraparound vulnerability due to the processing of maliciously crafted web content that may lead to arbitrary code execution.
Summary: CISA's KEV catalog, as of .
- CISA added CVE-2021-30952 to its Known Exploited Vulnerabilities (KEV) catalog on 5 Mar 2026.
- 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 26 Mar 2026.
- The CVE record was published on 24 Aug 2021, 1,654 days before it was added to KEV.
- The CVE record carries a CVSS v3.1 base score of 8.8 (High), taken from CISA's enrichment of the record.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 7% (percentile 94.1), 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
An integer overflow was addressed with improved input validation. This issue is fixed in tvOS 15.2, macOS Monterey 12.1, Safari 15.2, iOS 15.2 and iPadOS 15.2, watchOS 8.3. Processing maliciously crafted web content may lead to arbitrary code execution.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.
Weakness
- CWE-190: Integer Overflow or Wraparound
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 | |
| CVE record last updated | |
| CISA due date for the required action |
References
- support.apple.com
- support.apple.com
- support.apple.com
- support.apple.com
- support.apple.com
- [oss-security] 20220121 WebKitGTK and WPE WebKit Security Advisory WSA-2022-0001
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- CVE-2025-43520: Apple Multiple Products Classic Buffer Overflow Vulnerability
- CVE-2023-41974: Apple iOS and iPadOS Use-After-Free Vulnerability