Skip to main content

Mozilla Firefox CVE-2026-74936

| EUVDEUVD-2026-60745 CRITICAL
Use After Free (CWE-416)
2026-08-18 mozilla GHSA-m682-v78f-8q4j
Use After Free Information Disclosure Mozilla Memory Corruption Red Hat Suse
9.8
CVSS 3.1 · NVD
Share

Severity by source

NVD PRIMARY
9.8 CRITICAL
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
vuln.today AI
8.8 HIGH

Network-delivered via web content with low complexity and no privileges, but triggering requires the victim to visit malicious content, so UI:R; full memory-safety impact yields C/I/A:H within the content process (S:U).

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
7.5 HIGH
AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Red Hat
7.5 HIGH
qualitative

Primary rating from NVD.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Lifecycle Timeline

4
Analysis Generated
Aug 20, 2026 - 23:09 vuln.today
CVSS changed
Aug 20, 2026 - 20:52 NVD
9.8 (CRITICAL)
CVE Published
Aug 18, 2026 - 12:23 nvd
CRITICAL 9.8
CVE Published
Aug 18, 2026 - 12:23 cve.org
UNKNOWN (no severity yet)

DescriptionNVD

Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1.

AnalysisAI

Memory-corruption via a use-after-free in Firefox's JavaScript WebAssembly engine allows a remote attacker to corrupt heap memory and potentially achieve arbitrary code execution or information disclosure when a victim loads attacker-controlled content. All Firefox versions prior to Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1 are affected. …

Unlock full vulnerability intelligence

  • Risk assessment & exploitation conditions
  • Attack chain visualization
  • Remediation with exact patch versions
  • Threat intelligence from 22 sources
  • Personal watchlist & email alerts
Continue with Google Continue with GitHub

Free forever · No credit card required

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata

Access
Lure victim to malicious page
Delivery
Serve crafted JS/WebAssembly module
Exploit
Trigger use-after-free in Wasm engine
Execution
Reclaim freed memory with controlled data
Impact
Execute code or leak memory in content process
Sign in to reveal

Vulnerability AssessmentAI

Exploitation Exploitation requires the victim to load attacker-controlled web content that executes malicious WebAssembly in the affected Firefox/ESR build - i.e. … Additional conditions and limiting factors are described in the full assessment.
Risk Assessment The input CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:N, C:H/I:H/A:H = 9.8) treats this as unauthenticated remote code execution with no user interaction, but that conflicts with how a browser Wasm bug is actually triggered: exploitation realistically requires the victim to visit or render attacker-controlled content, i.e. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in.
Exploit Scenario An attacker hosts a malicious web page containing crafted JavaScript and WebAssembly that manipulates object lifetimes to trigger the use-after-free, then lures a victim to visit it (or serves it via a malvertising frame). Reclaiming the freed memory with controlled data lets the attacker corrupt the heap to leak sensitive memory or execute code in the content process. …
Remediation Upgrade to a fixed build: Firefox 154, Firefox ESR 140.14, or Firefox ESR 153.1 (Vendor-released patch: Firefox 154 / ESR 140.14 / ESR 153.1), per the Mozilla Foundation Security Advisories at https://www.mozilla.org/security/advisories/mfsa2026-74/ and the related mfsa2026-76 through mfsa2026-80 pages. … Detailed patch versions, workarounds, and compensating controls in full report.
Sign in to read full assessment

Recommended ActionAI

Within 24 hours, issue an urgent patch directive requiring all users to update Firefox to version 154 or Firefox ESR to version 140.14 or 153.1 depending on their deployment; for users unable to update immediately, restrict external web browsing to trusted domains only. …

Sign in for detailed remediation steps and compensating controls.

Threat intelligence, references, and detailed analysis are available after sign-in.

More in Mozilla

View all
CVE-2015-4495 HIGH POC
8.8 Aug 08

The PDF reader in Mozilla Firefox before 39.0.3, Firefox ESR 38.x before 38.1.1, and Firefox OS before 2.2 allows remote
CVE-2013-1690 HIGH POC
8.8 Jun 26

Mozilla Firefox before 22.0, Firefox ESR 17.x before 17.0.7, Thunderbird before 17.0.7, and Thunderbird ESR 17.x before

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-2017-3823 HIGH POC
8.8 Feb 01

An issue was discovered in the Cisco WebEx Extension before 1.0.7 on Google Chrome, the ActiveTouch General Plugin Conta
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-2013-0643 HIGH
8.8 Feb 27

The Firefox sandbox in Adobe Flash Player before 10.3.183.67 and 11.x before 11.6.602.171 on Windows and Mac OS X, and b

Same weakness CWE-416 – Use After Free

View all
CVE-2019-0708 CRITICAL POC
9.8
CVE-2015-5119 CRITICAL POC
9.8
CVE-2014-0322 HIGH POC
8.8
CVE-2012-4792 HIGH POC
8.8
CVE-2009-4324 HIGH POC
7.8
CVE-2015-0313 CRITICAL POC
9.8
CVE-2015-5122 CRITICAL POC
9.8
CVE-2013-2551 HIGH POC
8.8

Same technique Use After Free

View all
CVE-2015-5119 CRITICAL POC
9.8
CVE-2014-0322 HIGH POC
8.8
CVE-2012-4792 HIGH POC
8.8
CVE-2009-4324 HIGH POC
7.8
CVE-2015-0313 CRITICAL POC
9.8
CVE-2015-5122 CRITICAL POC
9.8
CVE-2013-2551 HIGH POC
8.8
CVE-2012-4969 HIGH POC
8.1

Vendor StatusVendor

SUSE

Severity: Important
Product Status
Container suse/kiosk/firefox-esr:140.14-75.12 Affected
SUSE Linux Enterprise Desktop 15 SP7 SUSE Linux Enterprise High Performance Computing 15 SP7 SUSE Linux Enterprise Module for Desktop Applications 15 SP7 SUSE Linux Enterprise Server 15 SP7 SUSE Linux Enterprise Server for SAP Applications 15 SP7 Fixed
SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS Fixed
SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS Fixed
SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS Fixed

Share

CVE-2026-74936 vulnerability details – vuln.today
Back

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy