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Mozilla Firefox CVE-2026-100764

| EUVDEUVD-2026-88916 HIGH
Buffer Overflow (CWE-119)
2026-09-29 mozilla GHSA-gr8j-74mg-qjgj
8.8
CVSS 3.1 · Vendor: mozilla
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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Host crafted WebGPU page
  2. Delivery
    Victim visits malicious page
  3. Exploit
    Trigger boundary violation in WebGPU
  4. Execution
    Corrupt content-process memory
  5. Impact
    Execute attacker code in process

Vulnerability Assessment

Weakness
CWE
ASVS 5.0
V15 - Secure Coding and Architecture Bounds checking, buffer size validation
MITRE ATT&CK

2 techniques across 2 tactics: Execution, Privilege Escalation

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Exploitation Conditions

Requires the victim to load attacker-controlled web content that exercises the Graphics: WebGPU component (UI:R), so exploitation depends on user interaction such as visiting a malicious or compromised page. WebGPU must be reachable/enabled in the victim's Firefox build (it is on by default in modern desktop Firefox). No authentication is required (PR:N) and complexity is low (AC:L), but the flaw is fixed in Firefox 157, so only pre-157 versions are exploitable. Scope is unchanged (S:U): impact is confined to the content process, not the host OS.

Impact

This is a mid-to-high priority browser flaw, not a drop-everything emergency. The CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H = 8.8) describes a network-reachable, unauthenticated, low-complexity memory-corruption bug requiring user interaction (victim must load attacker content), with total impact to the compromised content process. All three exploitation signals argue AGAINST imminent mass exploitation: SSVC gives Exploitation:none (no observed activity), Automatable:no (requires a victim to visit a page, so it cannot be sprayed at scale), and there is no EPSS score, no CISA KEV listing, and no public POC in the provided data. SSVC Technical Impact:total is consistent with the C:H/I:H/A:H memory-corruption class. The one point of tension: the description and 'Privilege Escalation' tag frame this as priv-esc, while CWE-119/'Buffer Overflow' and the S:U (unchanged scope) vector indicate in-process memory corruption rather than a cross-boundary sandbox escape - the 8.8 (not 9.6) score and S:U confirm it stays within the content process, so 'privilege escalation' here is best read as gaining code execution within that process, not host takeover. Net: a real bug worth patching promptly, but current evidence points to no active or automatable exploitation.

Exploit ScenarioDerived

An attacker hosts a malicious web page containing crafted WebGPU workloads that trigger an out-of-bounds/incorrect-boundary condition in Firefox's Graphics: WebGPU component. A victim running a vulnerable Firefox (pre-157) visits the page, and the boundary violation corrupts memory in the content process, enabling attacker-controlled code execution within that process. No public exploit code is identified at time of analysis, and exploitation requires user interaction (UI:R).

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).
No patch listed yet 0.2% exploitation probability (EPSS)

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AnalysisAIv1 – Sep 29, 2026

Privilege escalation in Mozilla Firefox versions prior to 157 arises from incorrect boundary conditions in the Graphics: WebGPU component, a CWE-119 buffer-bounds flaw that a remote, unauthenticated attacker can trigger when a victim loads attacker-controlled web content. Exploitation depends on user interaction (UI:R) - typically visiting a malicious or compromised page - and is rated CVSS 8.8 with high confidentiality, integrity and availability impact, though scope is unchanged (S:U) so the effect is confined to Firefox's content process rather than the host operating system. No public exploit code was identified and CISA's SSVC assessment records Exploitation: none, so this is a mid-to-high priority browser patch rather than an emergency; the issue is fixed in Firefox 157.

RemediationAI

Apply the vendor fix by upgrading Mozilla Firefox to 157 or later (or allowing the built-in updater to reach that release); Mozilla's advisory mfsa2026-97 (https://www.mozilla.org/security/advisories/mfsa2026-97/) and Bugzilla 2061290 (https://bugzilla.mozilla.org/show_bug.cgi?id=2061290) document the change, and every pre-157 build remains vulnerable. No patch data indicates a hotfix or backport distinct from the 157 release, so fleets that cannot move immediately should reduce exposure by turning off the WebGPU attack surface - setting the WebGPU preference (dom.webgpu.enabled) to false via about:config or an enterprise policy - accepting the trade-off that WebGPU-based web apps, games and GPU-accelerated demos will stop working or fall back to slower rendering. Because the flaw is reachable only after loading attacker-controlled content (UI:R) and its impact is scoped to the content process (S:U), keeping site isolation and the browser sandbox enabled limits blast radius while updates are staged, but this is a compensating control and not a substitute for upgrading. Given no public exploit code and an SSVC Exploitation rating of none, remediation can follow a normal patch cadence; verify version reporting for both rapid-release and ESR channels after deployment.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

WebGPU is the browser API that exposes GPU compute and rendering to web content, and in Firefox it is implemented in the Graphics: WebGPU component, which translates JavaScript/WebGPU calls into native GPU commands (via the wgpu backend and platform graphics drivers). CVE-2026-100764 is classified as CWE-119 (improper restriction of operations within the bounds of a memory buffer), but the description specifically attributes it to incorrect boundary conditions in that WebGPU path - meaning a length/size or index check is applied incorrectly, permitting out-of-bounds access when processing crafted WebGPU resources. The CVSS:3.1 vector AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H indicates the trigger is never authenticated, low complexity, and requires the victim to render attacker-supplied content, with impact contained to Firefox's own scope rather than escaping to the OS. The affected CPE range is cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* - effectively all builds before 157, with WebGPU enabled by default on modern desktop Firefox. The flaw is tracked as Mozilla Bugzilla 2061290, published in advisory mfsa2026-97, and cross-referenced in the EU as EUVD-2026-88916.

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  • Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

Vendor (mozilla) PRIMARY 8.8 HIGH
AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
vuln.today AI 8.8 HIGH

Network-delivered crafted WebGPU page, no auth, low complexity, but requires the victim to load content (UI:R); in-process memory corruption yields full C/I/A with unchanged scope.

3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
4.0 AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
SUSE MEDIUM

Primary rating from Vendor (mozilla).

CVSS VectorVendor: mozilla

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Lifecycle Timeline

2
CVE Published
Sep 29, 2026 - 12:35 cve.org
HIGH 8.8
CVE Published
Sep 29, 2026 - 12:35 cve.org
UNKNOWN (no severity yet)

DescriptionCVE.org

Privilege escalation due to incorrect boundary conditions in the Graphics: WebGPU component. This vulnerability was fixed in Firefox 157.

Executive ViewAI

Why It Matters

Organizations running Mozilla Firefox builds older than version 157 are exposed to CVE-2026-100764, a high-severity privilege-escalation and buffer-bounds flaw in the browser's WebGPU graphics component that is reached when a user opens attacker-controlled web content. Because confidentiality, integrity, and availability are all rated high and the attack path requires only routine web browsing, every unpatched Firefox user - including remote and hybrid staff - is a potential access point, although the effect is confined to the browser's content process rather than the underlying operating system. No public exploit code has been identified at time of analysis, so leadership should treat this as a scheduled, high-priority browser update rather than an emergency incident.

Business Impact: High
Compensating Controls

Apply vendor patch (Firefox 157).

Threat Intelligence Overview

EPSS Score
0.2%
Top 86% exploitable
Prevalence
Ubiquitous
Firefox is a globally deployed mainstream web browser
Data Quality
7 sources
Confidence: High

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity HIGH
CISA KEV No
Public POC No
EPSS 0.2%
Patch available No
Active threat No
Deciding rule
HIGH severity (CVSS 7.0-8.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision
Scheduled
Exploitation
None
System Exposure· derived
Open
Automatable
No
Human Impact
High
Technical Impact
Total

Priority Score

44
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +44
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Privilege escalation occurs when an attacker leverages flaws in access control mechanisms to gain permissions beyond what they were originally granted.

A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.

Affected Products (CPE)CVE.org

cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
CVE-2013-0758 CRITICAL POC
9.3 Jan 13

Mozilla Firefox before 18.0, Firefox ESR 10.x before 10.0.12 and 17.x before 17.0.2, Thunderbird before 17.0.2, Thunderb

CVE-2013-0753 CRITICAL POC
9.3 Jan 13

Use-after-free vulnerability in the serializeToStream implementation in the XMLSerializer component in Mozilla Firefox b

CVE-2012-3993 CRITICAL POC
9.3 Oct 10

The Chrome Object Wrapper (COW) implementation in Mozilla Firefox before 16.0, Firefox ESR 10.x before 10.0.8, Thunderbi

CVE-2013-1710 CRITICAL POC
10.0 Aug 07

The crypto.generateCRMFRequest function in Mozilla Firefox before 23.0, Firefox ESR 17.x before 17.0.8, Thunderbird befo

CVE-2014-8636 HIGH POC
7.5 Jan 14

The XrayWrapper implementation in Mozilla Firefox before 35.0 and SeaMonkey before 2.32 does not properly interact with

CVE-2013-0757 CRITICAL POC
9.3 Jan 13

The Chrome Object Wrapper (COW) implementation in Mozilla Firefox before 18.0, Firefox ESR 17.x before 17.0.2, Thunderbi

CVE-2014-1510 CRITICAL POC
9.8 Mar 19

The Web IDL implementation in Mozilla Firefox before 28.0, Firefox ESR 24.x before 24.4, Thunderbird before 24.4, and Se

CVE-2014-1511 CRITICAL POC
9.8 Mar 19

Mozilla Firefox before 28.0, Firefox ESR 24.x before 24.4, Thunderbird before 24.4, and SeaMonkey before 2.25 allow remo

CVE-2016-1960 HIGH POC
8.8 Mar 13

Integer underflow in the nsHtml5TreeBuilder class in the HTML5 string parser in Mozilla Firefox before 45.0 and Firefox

CVE-2015-0816 MEDIUM POC
5.0 Apr 01

Mozilla Firefox before 37.0, Firefox ESR 31.x before 31.6, and Thunderbird before 31.6 do not properly restrict resource

CVE-2015-0802 MEDIUM POC
5.0 Apr 01

Mozilla Firefox before 37.0 relies on docshell type information instead of page principal information for Window.webidl

CVE-2013-2566 MEDIUM POC
5.9 Mar 15

The RC4 algorithm, as used in the TLS protocol and SSL protocol, has many single-byte biases, which makes it easier for

Vendor StatusVendor

SUSE

Severity: Moderate
Product Status
SUSE Linux Enterprise Desktop 15 SP7 Affected
SUSE Linux Enterprise Desktop 15 SP7 Affected
SUSE Linux Enterprise Module for Desktop Applications 15 SP7 Affected
SUSE Linux Enterprise Module for Package Hub 15 SP7 Affected
SUSE Linux Enterprise Server 15 SP7 Affected

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