Analyst readout for executives and security teams
Plain-English summary
This is a high-severity Chrome for Mac browser flaw. A malicious webpage could potentially corrupt memory if an attacker persuades a user to perform specific UI gestures. The sources do not show active exploitation. Business urgency is mainly endpoint exposure: Mac users running Chrome before the fixed version should be updated quickly.
Executive priority
Treat as a high-priority endpoint update, especially for Mac-heavy teams. Required user interaction lowers immediacy compared with zero-click bugs, but browser memory corruption can still support serious compromise if users encounter malicious content.
Technical view
CVE-2026-9990 is a CWE-416 use-after-free in Chrome WebAppInstalls on Mac before 148.0.7778.216. The CVSS 3.1 score is 7.5 with network attack vector, high complexity, no privileges required, and required user interaction. Successful exploitation could affect confidentiality, integrity, and availability through heap corruption.
Likely exposure
Organizations are exposed where macOS endpoints run Google Chrome before 148.0.7778.216, including unmanaged or BYOD Macs. The issue is browser-side, not server-side, and requires user interaction with attacker-controlled HTML.
Exploitation context
The CVE states a remote attacker must convince a user to engage in specific UI gestures on a crafted HTML page. KEV status is false, and the provided sources do not state active exploitation or public weaponization.
Researcher notes
The public description is limited. The Chromium issue may contain restricted details. Do not assume affected platforms beyond Chrome on Mac or infer exploit availability. Validation should focus on version exposure and vendor release confirmation.
Mitigation direction
- Update Chrome on macOS to 148.0.7778.216 or later.
- Confirm enterprise browser update policies enforce the fixed version.
- Prioritize managed Macs used for email, web research, and privileged administration.
- Check Google Chrome release guidance for any additional vendor instructions.
Validation and detection
- Inventory macOS Chrome versions and identify systems below 148.0.7778.216.
- Verify update deployment completion through MDM or endpoint management reporting.
- Confirm unmanaged Macs and BYOD devices receive update instructions.
- Review browser crash or EDR telemetry for unusual Chrome heap-corruption indicators.
Public sources used
Based on public source material and reviewed before publication.
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-416: Exact CWE lookup
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Open ATT&CK lookupCVE-2026-9990 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
- High
- CVSS
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
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
1 official scoreWe 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:H/PR:N/UI:R/S:U/C:H/I:H/A:H 1.6 5.9 CISA-ADP Vulnerability scoring details
Base CVSS 3.1 score
7.5 HighVector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reserved CVE Program
The CVE ID was reserved by the assigning CNA.
- CVE published CVE Program
The CVE record was published.
- CVE updated CVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 source CVE List V5
- https://chromereleases.googleblog.com/2026/05/stable-channel-update-for-desktop_0877304591.html CVE reference, Chrome
- https://issues.chromium.org/issues/513128608 CVE reference, Chrome
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.
Use After Free
Use After Free represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.