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CVE Record

CVE-2026-43658: The issue was addressed with improved memory handling.

The issue was addressed with improved memory handling. This issue is fixed in Safari 26.5, iOS 26.5 and iPadOS 26.5, macOS Tahoe 26.5, tvOS 26.5, visionOS 26.5, watchOS 26.5. Processing maliciously crafted web content may lead to an unexpected Safari crash.

HighCVSS 8.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

CVE-2026-43658 is an Apple memory-handling flaw triggered when a user processes maliciously crafted web content. Apple says it may cause an unexpected Safari crash. Despite the crash wording, the CVSS 8.8 rating signals high potential impact. Apple fixed it across Safari and Apple platform updates.

Executive priority

Treat this as a high-priority patching item for Apple fleets. The main business risk is exposure through routine web browsing before updates are applied, even though current sources do not confirm active exploitation.

Technical view

The source bundle maps this to CWE-119 and CWE-120 memory boundary issues, with CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. User interaction is required through malicious web content. Apple describes the fix as improved memory handling in Safari 26.5 and Apple OS 26.5 releases.

Likely exposure

Organizations with unmanaged or delayed Apple updates are most exposed, especially users browsing the web on Safari, iOS, iPadOS, macOS, tvOS, visionOS, or watchOS versions before the fixed 26.5 releases listed by Apple.

Exploitation context

The provided sources do not show CISA KEV listing or confirmed active exploitation. The scenario is remote web content requiring user interaction. No public exploit details are included in the source bundle.

Researcher notes

Evidence is limited to vendor and CVE metadata. Apple’s advisory gives a concise impact statement and fix description, but no root-cause detail, exploitability notes, or indicators. Red Hat references exist in the bundle, but affected Apple products should not be broadened without advisory specifics.

Mitigation direction

  • Update Safari to 26.5 where applicable.
  • Update iOS and iPadOS to 26.5.
  • Update macOS Tahoe to 26.5.
  • Update tvOS, visionOS, and watchOS to 26.5 where deployed.
  • Check Apple and platform vendor guidance for any environment-specific instructions.

Validation and detection

  • Inventory Apple devices and Safari versions across managed fleets.
  • Confirm fixed 26.5 releases are installed on affected Apple platforms.
  • Review MDM compliance reports for delayed or failed updates.
  • Check exposure for shared, kiosk, lab, and executive devices.
  • Monitor Apple and Red Hat references for advisory updates.
Prepared
Confidence
medium
Sources
12

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-119: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
cwe · low confidence lookup

CWE-120: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2026-43658 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
High
CVSS
8.8 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
5Timeline events
2ADP providers
19Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: yesTechnical Impact: partial

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
8.8CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H2.85.9redhat-SADP
7.5CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N3.93.6CISA-ADP

Vulnerability scoring details

Base CVSS 3.1 score

8.8High
CVSS 3.1 vector shape for CVE-2026-43658Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. ADP timelineredhat-SADP

    Made public.

  4. ADP timelineredhat-SADP

    Reported to Red Hat.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
cvssV3_1other:ssvc
redhat-SADPwebkitgtk: Processing maliciously crafted web content may lead to an unexpected Safari crash
other:Red Hat severity ratingcvssV3_1
  • 2026-06-02T13:41:54.657Z: Reported to Red Hat.
  • 2026-06-02T00:00:00.000Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
AppleSafari0Listed
AppleiOS and iPadOS0Listed
ApplemacOS0Listed
AppletvOS0Listed
ApplevisionOS0Listed
ApplewatchOS0Listed
Weakness

CWE details

CWE-119CWE-120

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.