CVE-2026-20691Network attack vector

User fingerprinting via WebKit Sandboxing authorization failure

Published Mar 25, 2026 · Updated Mar 25, 2026

Authorization failure in WebKit Sandboxing in Apple products before 26.4 allows remote attackers to fingerprint users through a crafted webpage. Apple identifies improper authorization state management but has not disclosed the exact state or authorization check that accepts webpage-controlled input. Exploitation requires a user to render the crafted page; the reported consequence is fingerprinting, with no integrity or availability impact.

CVSS severity4.3
Medium
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authorization failure in WebKit Sandboxing in Apple products before 26.4 allows remote attackers to fingerprint users through a crafted webpage. Apple identifies improper authorization state management but has not disclosed the exact state or authorization check that accepts webpage-controlled input. Exploitation requires a user to render the crafted page; the reported consequence is fingerprinting, with no integrity or availability impact.

The record

CVE
CVE-2026-20691
Published
Mar 25, 2026
Updated
Mar 25, 2026
Vendor
Apple
Product
iOS and iPadOS
Classifications
CWE-497
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 25, 2026Record 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=0 <26.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Apple · iOS and iPadOSversion=0 <26.4
Apple · visionOSversion=0 <26.4
Apple · Safariversion=0 <26.4
Apple · macOSversion=0 <26.4
Apple · watchOSversion=0 <26.4

Published CVSS scores

4.3CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-497Exposure of Sensitive System Information to an Unauthorized Control Sphere

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.

Technologies

Your stack

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Your stack

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