CVE-2023-41991Known exploitation

Signature-validation bypass via improper certificate checks

Published Sep 21, 2023 · Updated Nov 4, 2025

Improper certificate validation in iOS and iPadOS before 16.7 and macOS before 13.6 lets local users bypass app signature checks. Apple identifies the Security component but has not published the failed certificate check or validation path. A malicious app must be launched for untrusted code to pass signature validation; Apple reports active exploitation only against iOS before 16.7.

CVSS severity5.5
Medium
EPSS probability4.55%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper certificate validation in iOS and iPadOS before 16.7 and macOS before 13.6 lets local users bypass app signature checks. Apple identifies the Security component but has not published the failed certificate check or validation path. A malicious app must be launched for untrusted code to pass signature validation; Apple reports active exploitation only against iOS before 16.7.

The record

CVE
CVE-2023-41991
Published
Sep 21, 2023
Updated
Nov 4, 2025
Vendor
Apple
Product
iOS and iPadOS
Classifications
CWE-295, T1553.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 21, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 4, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <16.7

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Apple · iOS and iPadOSversion=unspecified <16.7
Apple · macOSversion=unspecified <13.6

Published CVSS scores

5.5CISACVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationReported
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-295Improper Certificate Validation
T1553.002Subvert Trust Controls: Code Signing

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Reported exploitation

Technologies

Your stack

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Your stack

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