Security readout for executives and security teams
Plain-English summary
A malicious website could cross an origin boundary and reach script message handlers meant for another site. Successful abuse requires a user to visit the malicious page and is expected to expose limited information, with no stated integrity or availability impact. Apple has corrected the state-management flaw in listed Safari and operating-system releases.
Executive priority
Schedule a near-term Apple endpoint update rather than an emergency response. Prioritize users who frequently browse untrusted sites and devices handling sensitive information. Escalate if internal evidence indicates attempted exploitation or if Apple later reports active abuse.
Technical view
The flaw involves improper state management allowing cross-origin access to script message handlers. CVSS 3.1 is 4.3: network-accessible, low complexity, no privileges, user interaction required, and low confidentiality impact. CWE mappings are CWE-346 and CWE-79, although the supplied description does not establish arbitrary script execution.
Likely exposure
Potentially exposed assets are Apple devices running affected Safari, iOS, iPadOS, macOS, or visionOS releases without the listed fixes. Practical exposure requires interaction with a malicious website and relevant script message handlers. The bundle does not provide complete affected-version ranges, so version-level exposure beyond the fixed releases remains uncertain.
Exploitation context
The supplied KEV signal is false, and the sources provide no evidence of active exploitation. Exploitation is remotely initiated through a malicious website but requires user interaction. The stated impact is limited confidentiality loss; no integrity or availability impact is identified.
Researcher notes
The public description is sparse and attributes the issue to state management. It does not identify the vulnerable component, handler implementation, affected-version boundaries, or observable indicators. Researchers should avoid treating the CWE-79 mapping alone as proof of general cross-site scripting or code execution.
Mitigation direction
- Update Safari to version 26.4 where applicable.
- Update iOS and iPadOS to 18.7.7 or 26.4, as applicable.
- Update macOS Tahoe and visionOS to version 26.4.
- Consult the applicable Apple advisory for supported builds and deployment requirements.
Validation and detection
- Inventory Safari and Apple operating-system versions across managed devices.
- Compare each asset with its applicable fixed release listed by Apple.
- Confirm updates completed successfully through endpoint-management or local version reporting.
- Review Apple advisories before classifying older releases because complete affected ranges are not supplied.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
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-346: 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 lookupCWE-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. 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 lookupCVE-2026-28861 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 4.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
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.
SSVC decision data
CVSS vector scores
2 official scoresWe 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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N2.81.4CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N2.81.4redhat-SADPVulnerability scoring details
Base CVSS 3.1 score
4.3MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
Base CVSS 3.1 score
4.3MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- ADP timelineredhat-SADP
Made public.
- ADP timelineredhat-SADP
Reported to Red Hat.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
- 2026-03-30T12:37:40.953Z: Reported to Red Hat.
- 2026-03-28T20:00:00.000Z: Made public.
Source materials
- CVE List V5 sourceCVE List V5
- https://support.apple.com/en-us/126792CVE reference, apple
- https://support.apple.com/en-us/126793CVE reference, apple
- https://support.apple.com/en-us/126794CVE reference, apple
- https://support.apple.com/en-us/126799CVE reference, apple
- https://support.apple.com/en-us/126800CVE reference, apple
- https://access.redhat.com/security/cve/CVE-2026-28861CVE reference, redhat-SADP · vdb-entry, x_refsource_REDHAT
- RHBZ#2453007CVE reference, redhat-SADP · issue-tracking, x_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-28861.jsonCVE reference, redhat-SADP · x_sadp-csaf-vex
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Origin Validation Error
Origin Validation Error represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.