Apple · Multiple Products
CVE-2023-41991
Apple Multiple Products Improper Certificate Validation Vulnerability
What it is
A certificate validation issue was addressed. This issue is fixed in macOS Ventura 13.6, iOS 16.7 and iPadOS 16.7. A malicious app may be able to bypass signature validation. Apple is aware of a report that this issue may have been actively exploited against versions of iOS before iOS 16.7.
CISA: Apple iOS, iPadOS, macOS, and watchOS contain an improper certificate validation vulnerability that can allow a malicious app to bypass signature validation.
What to do
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Deadline for US federal agencies: October 16, 2023
More exploited flaws from Apple
| Added | Vulnerability | Product | Severity | Attack chance |
|---|---|---|---|---|
| Sep 29, 2026 | Out-of-Bounds Write | Multiple Products | High 8.8 | 26% |
| Mar 20, 2026 | Buffer Overflow | Multiple Products | High 8.8 | 1.7% |
| Mar 20, 2026 | Improper Locking | Multiple Products | High 7.8 | 0.4% |
| Mar 20, 2026 | Classic Buffer Overflow | Multiple Products | Medium 5.5 | 0.4% |
| Mar 5, 2026 | Integer Overflow or Wraparound | Multiple Products | High 8.8 | 7.0% |
| Mar 5, 2026 | Use-After-Free | Multiple Products | High 8.8 | 4.0% |
| Feb 12, 2026 | Multiple Buffer Overflow | Multiple Products | High 7.8 | 1.7% |
| Dec 15, 2025 | Use-After-Free WebKit | Multiple Products | High 8.8 | 26% |
Sources: Known Exploited Vulnerabilities (CISA, public domain), CVE records (cve.org) and EPSS (FIRST). The chance of attacks is the EPSS estimate that someone will try to exploit the flaw in the next 30 days.