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CVE Record

CVE-2026-20644: The issue was addressed with improved memory handling.

The issue was addressed with improved memory handling. This issue is fixed in Safari 26.3, iOS 18.7.5 and iPadOS 18.7.5, iOS 26.3 and iPadOS 26.3, macOS Tahoe 26.3, visionOS 26.3. Processing maliciously crafted web content may lead to an unexpected process 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-2026-20644 is an Apple web-content memory-handling flaw. A malicious webpage could cause an affected browser or system process to crash. Apple fixed it in Safari 26.3, iOS/iPadOS 18.7.5 and 26.3, macOS Tahoe 26.3, and visionOS 26.3.

Executive priority

Treat as a high-priority browser and endpoint patching item. The public evidence supports serious potential impact, but not confirmed active exploitation. Prioritize user-facing Apple systems and executives or staff exposed to untrusted links.

Technical view

Apple describes the issue as improved memory handling for maliciously crafted web content causing unexpected process crash. The record carries CVSS 8.8 with network attack vector, low complexity, no privileges, and user interaction required. CWE mappings include memory corruption classes such as out-of-bounds write and use-after-free.

Likely exposure

Exposure is most likely on Apple endpoints or browsers below the fixed releases, especially users who browse untrusted web content. The source bundle does not provide precise vulnerable version ranges beyond fixed release names.

Exploitation context

The source bundle marks KEV as false and provides no cited evidence of active exploitation. Exploitation would require a user to process maliciously crafted web content, according to the CVSS user-interaction requirement and Apple description.

Researcher notes

Public details are sparse. Apple states memory handling was improved and impact is process crash; the CVSS vector reports high confidentiality, integrity, and availability impact. Avoid assuming code execution or affected third-party products without vendor confirmation.

Mitigation direction

  • Update Safari to 26.3 where applicable.
  • Update iOS and iPadOS to 18.7.5 or 26.3.
  • Update macOS Tahoe systems to 26.3.
  • Update visionOS devices to 26.3.
  • Check Apple guidance for any deployment-specific caveats.

Validation and detection

  • Inventory Apple OS and Safari versions across managed devices.
  • Confirm endpoints meet or exceed the fixed releases.
  • Review vulnerability scanner findings for CVE-2026-20644 status.
  • Check Apple advisory pages for the exact platform release applied.
Prepared
Confidence
medium
Sources
9

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.

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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
cwe · low confidence lookup

CWE-416: 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-787: 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-2026-20644 mapping review

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

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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
20Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical 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
6.5CVSS 3.1MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H2.83.6CISA-ADP

Vulnerability scoring details

Base CVSS 3.1 score

8.8High
CVSS 3.1 vector shape for CVE-2026-20644Attack 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 process crash
other:Red Hat severity ratingcvssV3_1
  • 2026-03-18T20:20:25.753Z: Reported to Red Hat.
  • 2026-03-18T00:00:00.000Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
AppleSafari0Listed
AppleiOS and iPadOS0, 0Listed
ApplemacOS0Listed
ApplevisionOS0Listed
Weakness

CWE details

CWE-119CWE-120CWE-416CWE-787

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