CVE-2026-4723 | Mozilla Firefox up to 148 JavaScript Engine use after free

VDB-352774 · CVE-2026-4723 · GCVE-0-2026-4723 MOZILLA FIREFOX UP TO 148 JAVASCRIPT ENGINE USE AFTER FREE HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 6.0 $5k-$25k 2.14+ Summaryinfo A vulnerability, which was classified as critical, was found in Mozilla Firefox up to 148. This issue affects some unknown processing of the component JavaScript Engine. Executing a manipulation can lead to use after free. The identification of this vulnerability is CVE-2026-4723. The attack may be launched remotely. There is no exploit available. You should upgrade the affected component. Detailsinfo A vulnerability classified as critical was found in Mozilla Firefox up to 148. This vulnerability affects some unknown functionality of the component JavaScript Engine. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes: Use-after-free in the JavaScript Engine component. This vulnerability affects Firefox < 149. The advisory is available at bugzilla.mozilla.org. This vulnerability was named CVE-2026-4723 since 03/24/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Successful exploitation requires user interaction by the victim. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 03/24/2026). Upgrading to version 149 eliminates this vulnerability. Productinfo Type Web Browser Vendor Mozilla Name Firefox Version 148 License open-source Website Vendor: https://www.mozilla.org/ Product: https://www.mozilla.org/en-US/firefox/ CPE 2.3info 🔒 CPE 2.2info 🔒 CVSSv4info VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv3info VulDB Meta Base Score: 6.3 VulDB Meta Temp Score: 6.0 VulDB Base Score: 6.3 VulDB Temp Score: 6.0 VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv2info Vector Complexity Authentication Confidentiality Integrity Availability Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock VulDB Base Score: 🔒 VulDB Temp Score: 🔒 VulDB Reliability: 🔍 Exploitinginfo Class: Use after free CWE: CWE-416 / CWE-119 CAPEC: 🔒 ATT&CK: 🔒 Physical: No Local: No Remote: Yes Availability: 🔒 Status: Not defined Price Prediction: 🔍 Current Price Estimation: 🔒 0-Day Unlock Unlock Unlock Unlock Today Unlock Unlock Unlock Unlock Threat Intelligenceinfo Interest: 🔍 Active Actors: 🔍 Active APT Groups: 🔍 Countermeasuresinfo Recommended: Upgrade Status: 🔍 0-Day Time: 🔒 Upgrade: Firefox 149 Timelineinfo 03/24/2026 Advisory disclosed 03/24/2026 +0 days CVE reserved 03/24/2026 +0 days VulDB entry created 03/24/2026 +0 days VulDB entry last update Sourcesinfo Vendor: mozilla.org Product: mozilla.org Advisory: bugzilla.mozilla.org Status: Confirmed CVE: CVE-2026-4723 (🔒) GCVE (CVE): GCVE-0-2026-4723 GCVE (VulDB): GCVE-100-352774 Entryinfo Created: 03/24/2026 14:46 Changes: 03/24/2026 14:46 (57) Complete: 🔍 Cache ID: 99:433:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸