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PatchSiren cyber security CVE debrief

CVE-2021-30952 Apple CVE debrief

CVE-2021-30952 is an Apple multiple-products integer overflow or wraparound vulnerability that CISA lists in its Known Exploited Vulnerabilities catalog. Because it is in KEV, defenders should treat it as a priority remediation item even though the supplied corpus does not include affected product versions or a CVSS score. Follow Apple’s vendor guidance and the CISA due date to reduce exposure.

Vendor
Apple
Product
Multiple Products
CVSS
Unknown
CISA KEV
Listed
Original CVE published
2026-03-05
Original CVE updated
2026-03-05
Advisory published
2026-03-05
Advisory updated
2026-03-05

Who should care

Teams managing Apple endpoints and related Apple product estates, plus vulnerability management, endpoint security, and incident response teams.

Technical summary

The issue is described as an integer overflow or wraparound affecting Apple multiple products. CISA’s KEV entry indicates known exploitation and points defenders to Apple mitigation guidance. The supplied corpus does not identify specific affected versions, exploit conditions, or severity scoring.

Defensive priority

Urgent

Recommended defensive actions

  • Inventory Apple products in your environment and compare them against Apple’s vendor advisories referenced by CISA KEV.
  • Apply Apple mitigations or updates as soon as possible, using the vendor guidance cited in the KEV metadata (HT212975, HT212976, HT212978, HT212980, HT212982).
  • Prioritize remediation before the KEV due date of 2026-03-26 and track completion in your vulnerability management process.
  • If mitigations are unavailable, use compensating controls and follow applicable CISA BOD 22-01 guidance for cloud services.
  • Validate that exposed systems are no longer vulnerable and monitor for suspicious activity consistent with active exploitation.

Evidence notes

The supplied corpus includes the CISA KEV JSON entry, which marks CVE-2021-30952 as known exploited and identifies Apple as the vendor. It also references Apple support articles (HT212975, HT212976, HT212978, HT212980, HT212982) for mitigation guidance and the official CVE/NVD records for identifier corroboration. No affected-version list, CVSS score, or exploit details were provided in the supplied materials.

Official resources

Public debrief based only on the supplied official sources and KEV metadata; no unsupported technical detail has been added.