CVE-2026-43708Network attack vector

Cross-origin cookie disclosure via skipped partitioning

Published Jun 29, 2026 · Updated Jun 29, 2026

Cookie disclosure in Apple Safari, iOS, iPadOS, and macOS before 26.5.2 allows remote attackers to exfiltrate cross-origin cookies. WebKit NetworkSessionCocoa::createWebSocketTask probes _setAllowOnlyPartitionedCookies: on a possibly nil mutable request, so the partitioning block is skipped and CFNetwork attaches unpartitioned cookies to a cross-site WebSocket handshake. Exploitation requires a user to visit attacker-controlled web content that opens the cross-site WebSocket; the consequence is disclosure of cookie-bound state to the destination endpoint.

CVSS severity4.3
Medium
EPSS probability0.41%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cookie disclosure in Apple Safari, iOS, iPadOS, and macOS before 26.5.2 allows remote attackers to exfiltrate cross-origin cookies. WebKit NetworkSessionCocoa::createWebSocketTask probes _setAllowOnlyPartitionedCookies: on a possibly nil mutable request, so the partitioning block is skipped and CFNetwork attaches unpartitioned cookies to a cross-site WebSocket handshake. Exploitation requires a user to visit attacker-controlled web content that opens the cross-site WebSocket; the consequence is disclosure of cookie-bound state to the destination endpoint.

The record

CVE
CVE-2026-43708
Published
Jun 29, 2026
Updated
Jun 29, 2026
Vendor
Apple
Product
iOS and iPadOS
Classifications
CWE-20, T1539
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 29, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 29, 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 <26.5.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Apple · iOS and iPadOSversion=0 <26.5.2
Apple · Safariversion=0 <26.5.2
Apple · macOSversion=0 <26.5.2

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-20Improper Input Validation
T1539Steal Web Session Cookie

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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