Analyst readout for executives and security teams
Plain-English summary
Chrome versions before 148.0.7778.216 contain a high-severity memory safety flaw in the browser UI. A malicious webpage could potentially help an attacker escape Chrome’s sandbox after user interaction, raising the business urgency for managed desktop browser updates.
Executive priority
Treat this as a prompt patching item for desktop fleets, not a confirmed breach signal. The potential sandbox escape impact is serious, but the available sources do not confirm active exploitation.
Technical view
CVE-2026-9951 is a CWE-416 use-after-free in Google Chrome UI. The CVSS 3.1 score is 8.3 with network attack vector, high complexity, no privileges required, user interaction required, changed scope, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is most likely on endpoints running Google Chrome earlier than 148.0.7778.216, especially unmanaged or slow-updating desktops where users browse arbitrary websites.
Exploitation context
The bundle does not show CISA KEV listing or any cited source confirming active exploitation. The described attack path requires a crafted HTML page and user interaction; Chromium issue details may be limited.
Researcher notes
The strongest source-backed details are the Chrome version boundary, CWE-416 class, and CVSS vector. Do not infer exploit maturity, affected Chromium-based browsers, or workaround details from the provided bundle alone.
Mitigation direction
- Update Google Chrome to 148.0.7778.216 or later.
- Prioritize managed desktop fleets and high-risk user groups.
- Confirm enterprise browser update policies are enforcing current stable versions.
- Monitor Google Chrome release guidance for any follow-up corrections.
- Check CISA KEV before escalation decisions based on exploitation status.
Validation and detection
- Inventory Chrome versions across managed endpoints.
- Confirm no endpoints remain below 148.0.7778.216.
- Review EDR or device-management telemetry for update failures.
- Validate browser auto-update controls on representative systems.
- Track the Chromium issue and Chrome release post for new details.
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
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 lookupPrivilege behavior lookup
The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-9951 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
- 8.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/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:C/C:H/I:H/A:H 1.6 6 CISA-ADP Vulnerability scoring details
Base CVSS 3.1 score
8.3 HighVector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/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/503873388 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.