CVE-2026-28917Network attack vector

Process crash via malformed WebKit input

Published May 11, 2026 · Updated May 11, 2026

Improper input validation in WebKit in affected Apple operating systems allows remote attackers to crash a process via crafted web content. Apple identifies WebKit Bugzilla 310527 as the locus, but the report is nonpublic, so the exact input and incorrect validation operation are undisclosed. User interaction is required to process the content, and the documented consequence is an unexpected process crash rather than system shutdown or data compromise.

CVSS severityUnavailable
Unscored
EPSS probability0.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in WebKit in affected Apple operating systems allows remote attackers to crash a process via crafted web content. Apple identifies WebKit Bugzilla 310527 as the locus, but the report is nonpublic, so the exact input and incorrect validation operation are undisclosed. User interaction is required to process the content, and the documented consequence is an unexpected process crash rather than system shutdown or data compromise.

The record

CVE
CVE-2026-28917
Published
May 11, 2026
Updated
May 11, 2026
Vendor
Apple
Product
iOS and iPadOS
Classifications
CWE-20, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 11, 2026CVE publishedPublication date reported by the CVE source.
  2. May 11, 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 <18.7.9
  2. Affected versionversion=0 <26.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Apple · iOS and iPadOSversion=0 <18.7.9; version=0 <26.5
Apple · visionOSversion=0 <26.5
Apple · tvOSversion=0 <26.5
Apple · macOSversion=0 <26.5
Apple · watchOSversion=0 <26.5

Published CVSS scores

No CVSS assessment is available in this record.

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-20Improper Input Validation
T1499.004Endpoint Denial of Service: Application or System Exploitation

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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