CVE-2026-28955Network attack vector

Remote code execution via WebCore object use-after-free

Published May 11, 2026 · Updated May 11, 2026

Use-after-free in WebKit in affected Apple operating systems allows remote attackers to execute code through malicious web content. The WebCore style resolver in Web Inspector operates on an object without first validating that it still exists, leaving a stale reference. Exploitation requires the target to visit a malicious page or open a malicious file, and successful exploitation runs code in the browser process.

CVSS severity8.8
High
EPSS probability0.69%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in WebKit in affected Apple operating systems allows remote attackers to execute code through malicious web content. The WebCore style resolver in Web Inspector operates on an object without first validating that it still exists, leaving a stale reference. Exploitation requires the target to visit a malicious page or open a malicious file, and successful exploitation runs code in the browser process.

The record

CVE
CVE-2026-28955
Published
May 11, 2026
Updated
May 11, 2026
Vendor
Apple
Product
iOS and iPadOS
Classifications
CWE-119, CWE-120, T1203
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

7.5TrendAI Zero Day InitiativeCVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
8.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

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-119Improper Restriction of Operations within the Bounds of a Memory Buffer
CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1203Exploitation for Client Execution

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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