CVE-2026-100811
Description
A flaw was found in Firefox. A use-after-free memory flaw in the Document Object Model (DOM) Core and HTML component allows a remote attacker to perform a sandbox escape. By enticing a user to visit a specially crafted web page, an attacker can leverage this vulnerability to execute arbitrary code outside the browser's restricted sandbox environment.
Statement
An IMPORTANT severity use-after-free flaw was found in the Firefox web browser's Document Object Model (DOM) Core and HTML component. A remote attacker could entice a victim to visit a specially crafted web page to trigger the use-after-free condition and execute arbitrary code outside of the browser's restricted sandbox environment, resulting in a sandbox escape and potential compromise of the victim's user session. The firefox component as shipped in affected Red Hat product streams is affected by this flaw; no affected Red Hat product stream is currently distinguished as not affected. Red Hat Product Security has rated this flaw with a CVSS 3.1 score of 6.1 (moderate) (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N), which is substantially lower than the 9.6 (critical) score assigned by CISA; the difference is mainly attributable to Red Hat's lower confidentiality and integrity impact assessment (C:L/I:L/A:N versus C:H/I:H/A:H).
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.1 | N/A | 9.6 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | Required | N/A | Required |
| Scope | Changed | N/A | Changed |
| Confidentiality | Low | N/A | High |
| Integrity Impact | Low | N/A | High |
| Availability Impact | None | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
If the expired pointer is used in a read operation, an attacker might be able to control data read in by the application.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
If the expired pointer references a memory location that is not accessible to the product, or points to a location that is "malformed" (such as NULL) or larger than expected by a read or write operation, then a crash may occur.
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
If the expired pointer is used in a function call, or points to unexpected data in a write operation, then code execution may be possible.
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