CVE-2026-6779 | Mozilla Firefox up to 149 JavaScript Engine Remote Code Execution

VDB-358476 · CVE-2026-6779 · GCVE-0-2026-6779 MOZILLA FIREFOX UP TO 149 JAVASCRIPT ENGINE REMOTE CODE EXECUTION HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 6.0 $5k-$25k 1.74+ Summaryinfo A vulnerability was found in Mozilla Firefox up to 149. It has been declared as critical. This affects an unknown function of the component JavaScript Engine. The manipulation results in an unknown weakness. This vulnerability is identified as CVE-2026-6779. The attack can be executed remotely. There is not any exploit available. It is recommended to upgrade the affected component. Detailsinfo A vulnerability was found in Mozilla Firefox up to 149. It has been classified as critical. Affected is some unknown processing of the component JavaScript Engine. The impact remains unknown. CVE summarizes: Other issue in the JavaScript Engine component. This vulnerability was fixed in Firefox 150. The advisory is shared for download at bugzilla.mozilla.org. This vulnerability is traded as CVE-2026-6779 since 04/21/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 04/21/2026). Upgrading to version 150 eliminates this vulnerability. Productinfo Type Web Browser Vendor Mozilla Name Firefox Version 149 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: Remote Code Execution CWE: Unknown 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 150 Timelineinfo 04/21/2026 Advisory disclosed 04/21/2026 +0 days CVE reserved 04/21/2026 +0 days VulDB entry created 04/21/2026 +0 days VulDB entry last update Sourcesinfo Vendor: mozilla.org Product: mozilla.org Advisory: bugzilla.mozilla.org Status: Confirmed CVE: CVE-2026-6779 (🔒) GCVE (CVE): GCVE-0-2026-6779 GCVE (VulDB): GCVE-100-358476 Entryinfo Created: 04/21/2026 16:05 Changes: 04/21/2026 16:05 (54) Complete: 🔍 Cache ID: 99:BBE:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸