CVE-2026-28991

Description

An out-of-bounds read was addressed with improved bounds checking. This issue is fixed in iOS 26.5 and iPadOS 26.5, macOS Tahoe 26.5, tvOS 26.5, visionOS 26.5, watchOS 26.5. An app may be able to cause a denial-of-service.

Overview

State: PUBLISHED
Assigner (CNA): apple
CVSS severity: high
CVSS score: 7.5 / 10
CVSS vector: AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Effective score: 7.5 / 10 HIGH source: CNA overview
CWE(s): —
Reserved: 2026-03-03
Published: 2026-05-11 22:08 UTC
Last updated: 2026-05-12 19:24 UTC
Source: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/28xxx/CVE-2026-28991.json
Linked Threat: CVE-2026-28991 — CVE-2026-28991

NVD triage scoring NVD CVE 2.0

Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.

NVD published: 2026-05-11 21:18:59 UTC
NVD last modified: 2026-05-13 14:07:52 UTC
NVD CVSS v3.1: 7.5 / 10 HIGH source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
NVD CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Exploitability subscore: 3.9 / 10
Impact subscore: 3.6 / 10
EPSS score: 0.0006 (probability of exploitation in next 30 days)
EPSS percentile: 19.18% vs all CVEs — higher = more likely to be exploited, as of 2026-05-25

NVD-assigned CWE(s): CWE-125 (differs from the CNA list above)

European Union Vulnerability Database ENISA EUVD

ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.

EUVD ID: EUVD-2026-29284
Assigner: apple
Published: May 11, 2026, 8:08:10 PM
Updated: May 12, 2026, 5:24:25 PM
EUVD base score (CVSS 3.1): 7.5 / 10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EUVD-reported EPSS: 0.0600
Vendors: Apple
Products: iOS and iPadOS (0 <26.5)

macOS (0 <26.5)

visionOS (0 <26.5)

tvOS (0 <26.5)

watchOS (0 <26.5)

ENISA description: An out-of-bounds read was addressed with improved bounds checking. This issue is fixed in iOS 26.5 and iPadOS 26.5, macOS Tahoe 26.5, tvOS 26.5, visionOS 26.5, watchOS 26.5. An app may be able to cause a denial-of-service.

EUVD references (5)

Affected products (5)

Vendor	Product	Versions	Platforms
Apple	iOS and iPadOS	`0` (affected)	—
Apple	macOS	`0` (affected)	—
Apple	tvOS	`0` (affected)	—
Apple	visionOS	`0` (affected)	—
Apple	watchOS	`0` (affected)	—

Affected products — CPE 2.3 (6) NVD

NVD's normalized CPE 2.3 matchers, used by vendor tools (vulnerability scanners, asset managers) for automated detection. Compare with the CNA's free-text "Affected products" section above.

cpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:tvos:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:visionos:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:watchos:*:*:*:*:*:*:*:*

Vendor references (5)

References embedded in the original CVE record by the assigning CNA.

MITRE references (5) cveawg.mitre.org

Pulled from MITRE's CVE Services API by the 🛰 Backfill from MITRE button.

Web references (7)

DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.

https://attackerkb.com/topics/CVE-2026-28991 rapid7:attackerkb.com
https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-29284 rapid7:euvd.enisa.europa.eu
http://cwe.mitre.org/data/definitions/125.html rapid7:cwe.mitre.org
https://www.first.org/epss/ tenable:www.first.org
https://isc.sans.edu/diary/rss/32976 tenable:isc.sans.edu
https://nvd.nist.gov/vuln/detail/CVE-2026-28991 tenable:nvd.nist.gov
https://www.cve.org/CVERecord?id=CVE-2026-28991 tenable:www.cve.org

NVD-tagged references (5)

Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.

https://support.apple.com/en-us/127110 product-security@apple.com Release NotesVendor Advisory
https://support.apple.com/en-us/127115 product-security@apple.com Release NotesVendor Advisory
https://support.apple.com/en-us/127118 product-security@apple.com Release NotesVendor Advisory
https://support.apple.com/en-us/127119 product-security@apple.com Release NotesVendor Advisory
https://support.apple.com/en-us/127120 product-security@apple.com Release NotesVendor Advisory

Remediations (15)

Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.

Patch Tuesday - Cisco Talos Blog

web:blog.talosintelligence.com

Microsoft Patch Tuesday for October 2025 — Snort rules and prominent vulnerabilities Microsoft has released its monthly security update for October 2025, addressing 175 Microsoft CVEs and 21 non-Microsoft CVEs . Among these, 17 vulnerabilities are considered critical and 11 are flagged as important and considered more likely to be exploited.

2026-05-23 21:00 UTC
CISA Warns of Exploited Microsoft Defender 0-Day Flaws

web:cyberpress.org

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has added two actively exploited Microsoft Defender vulnerabilities to its Known Exploited Vulnerabilities (KEV) catalog, issuing an urgent remediation directive for federal agencies with a due date of June 3, 2026 .

2026-05-23 21:00 UTC
CISA Warns of Microsoft Defender 0-Day Vulnerabilities Exploited in Attacks

web:cybersecuritynews.com

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has added two critical Microsoft Defender vulnerabilities to its Known Exploited Vulnerabilities (KEV) catalog, warning organizations of active exploitation risks. The flaws, tracked as CVE - 2026 -45498 and CVE - 2026 -41091, impact Microsoft Defender and could allow attackers to disrupt systems or escalate privileges. Both ...

2026-05-23 21:00 UTC
Security Update Guide - Microsoft

web:portal.msrc.microsoft.com

The Security Update Guide provides information on the latest Microsoft security updates, helping users understand and address potential vulnerabilities effectively.

2026-05-23 21:00 UTC
April 2026 Patch Tuesday: Updates and Analysis | CrowdStrike

web:www.crowdstrike.com

Microsoft's April 2026 Patch Tuesday addresses 164 CVEs , featuring 8 Critical vulnerabilities, one exploited zero-day, and one disclosed zero-day.

2026-05-23 21:00 UTC
Microsoft patches two zero-day flaws in Defender - CSO Online

web:www.csoonline.com

Microsoft released emergency fixes for two zero-day vulnerabilities in the malware protection components of Microsoft Defender. The flaws allow local attackers to gain system-level privileges or ...

2026-05-23 21:00 UTC
2 New Microsoft Defender Zero-Days Exploited—Patch Now ... - Forbes

web:www.forbes.com

Microsoft has confirmed an emergency security update as CISA warns that two new Defender zero-days are being exploited by attackers.

2026-05-23 21:00 UTC
Microsoft Defender vulnerabilities exploited in the wild (CVE-2026 ...

web:www.helpnetsecurity.com

Attackers are actively exploiting two Microsoft Defender vulnerabilities ( CVE - 2026 -41091 and CVE - 2026 -45498), Microsoft acknowledged.

2026-05-23 21:00 UTC
Oracle Critical Patch Update Advisory - April 2026

web:www.oracle.com

This Critical Patch Update contains 481 new security patches across the product families listed below. Please note that an MOS note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at April 2026 Critical Patch Update: Executive Summary and Analysis.

2026-05-23 21:00 UTC
Patch Tuesday May 2026: Security Updates & CVE Analysis

web:zecurit.com

Get the complete breakdown of Microsoft's May 2026 Patch Tuesday. We analyze the latest security updates and all critical CVEs .

2026-05-23 21:00 UTC
Microsoft and Adobe Patch Tuesday, April 2026 Security Update Review

web:blog.qualys.com

With Qualys Policy Audit's out-of-the-box mitigation or Compensatory Controls, which reduce the risk of a vulnerability being exploited because the remediation ( fix / patch ) cannot be done immediately, these security controls are not recommended by any industry standards, such as CIS and DISA-STIG.

2026-05-26 02:50 UTC
CISA Issues Alert on Exploited Microsoft Defender Zero-Day ... - GBHackers

web:gbhackers.com

CISA has issued an urgent alert warning organizations about two newly disclosed zero-day vulnerabilities affecting Microsoft Defender, both added to the Known Exploited Vulnerabilities (KEV) catalog on May 20, 2026 . CVE - 2026 -45498: Microsoft Defender DoS Vulnerability CVE - 2026 -45498 is a denial-of-service (DoS) vulnerability in Microsoft Defender that can cause the security service to stop ...

2026-05-26 02:50 UTC
Security Update Guide - Microsoft

web:msrc.microsoft.com

The Microsoft Security Response Center (MSRC) investigates all reports of security vulnerabilities affecting Microsoft products and services, and provides the information here as part of the ongoing effort to help you manage security risks and help keep your systems protected.

2026-05-26 02:50 UTC
Microsoft warns of new Defender zero-days exploited in attacks

web:www.bleepingcomputer.com

On Wednesday, Microsoft started rolling out security patches for two Defender vulnerabilities that have been exploited in zero-day attacks.

2026-05-26 02:50 UTC
February's Patch Tuesday release fixes 59 flaws ... - Computerworld

web:www.computerworld.com

Each month, the team at Readiness analyzes the latest Patch Tuesday updates from Microsoft and provides detailed, actionable testing guidance. The company's Patch Tuesday release for February ...

2026-05-26 02:50 UTC

AI Forensic Analysis

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Raw JSON

The full cvelistV5 record. Download as CVE-2026-28991.json.

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              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
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              "baseScore": 7.5,
              "baseSeverity": "HIGH",
              "confidentialityImpact": "NONE",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
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