Cross-origin handler access via incorrect state management
Published Mar 25, 2026 · Updated Mar 25, 2026
Same-origin-policy bypass in Safari and Apple operating systems before 18.7.7 or 26.4 allows remote attackers to access cross-origin handlers. Apple identifies the locus as WebKit script message-handler origin state but has not disclosed the incorrect state transition or validation path. Exploitation requires malicious web content to run in the browser; the documented consequence is access to handlers intended for another origin.
Summary
What happened
Same-origin-policy bypass in Safari and Apple operating systems before 18.7.7 or 26.4 allows remote attackers to access cross-origin handlers. Apple identifies the locus as WebKit script message-handler origin state but has not disclosed the incorrect state transition or validation path. Exploitation requires malicious web content to run in the browser; the documented consequence is access to handlers intended for another origin.
The record
- CVE
- CVE-2026-28861
- Published
- Mar 25, 2026
- Updated
- Mar 25, 2026
- Vendor
- Apple
- Product
- iOS and iPadOS
- Classifications
- CWE-346, T1189
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 25, 2026CVE publishedPublication date reported by the CVE source.
- 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.
- Affected versionversion=0 <18.7.7
- Affected versionversion=0 <26.4
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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