CVE-2026-28907Network attack vector

Content Security Policy bypass via improper input validation

Published May 11, 2026 · Updated May 11, 2026

Input validation in WebKit on affected Apple operating systems allows remote attackers to bypass Content Security Policy via crafted web content. Apple identifies WebKit Bugzilla 308675 and states that improved input validation corrected the flaw, but public material does not identify the malformed input or validation branch that accepted it. Exploitation requires a user to process attacker-controlled web content; the policy bypass permits content that the site's CSP intended to block, without a reported availability impact.

CVSS severity8.1
High
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

Input validation in WebKit on affected Apple operating systems allows remote attackers to bypass Content Security Policy via crafted web content. Apple identifies WebKit Bugzilla 308675 and states that improved input validation corrected the flaw, but public material does not identify the malformed input or validation branch that accepted it. Exploitation requires a user to process attacker-controlled web content; the policy bypass permits content that the site's CSP intended to block, without a reported availability impact.

The record

CVE
CVE-2026-28907
Published
May 11, 2026
Updated
May 11, 2026
Vendor
Apple
Product
iOS and iPadOS
Classifications
CWE-20, CWE-116
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

8.1CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
CWE-116Improper Encoding or Escaping of Output

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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