CVE-2026-4727 | Mozilla Firefox up to 148 Libraries denial of service

VDB-352777 · CVE-2026-4727 · GCVE-0-2026-4727 MOZILLA FIREFOX UP TO 148 LIBRARIES DENIAL OF SERVICE HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 4.1 $0-$5k 1.95+ Summaryinfo A vulnerability was found in Mozilla Firefox up to 148. It has been classified as problematic. The impacted element is an unknown function of the component Libraries. This manipulation causes denial of service. This vulnerability is tracked as CVE-2026-4727. The attack is possible to be carried out remotely. No exploit exists. Upgrading the affected component is recommended. Detailsinfo A vulnerability has been found in Mozilla Firefox up to 148 and classified as problematic. Affected by this vulnerability is an unknown code block of the component Libraries. The manipulation with an unknown input leads to a denial of service vulnerability. The CWE definition for the vulnerability is CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. As an impact it is known to affect availability. The summary by CVE is: Denial-of-service in the Libraries component in NSS. This vulnerability affects Firefox < 149. The advisory is shared at bugzilla.mozilla.org. This vulnerability is known as CVE-2026-4727 since 03/24/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 03/24/2026). MITRE ATT&CK project uses the attack technique T1499 for this issue. 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: 4.3 VulDB Meta Temp Score: 4.1 VulDB Base Score: 4.3 VulDB Temp Score: 4.1 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: Denial of service CWE: CWE-404 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-2026-4727 (🔒) GCVE (CVE): GCVE-0-2026-4727 GCVE (VulDB): GCVE-100-352777 Entryinfo Created: 03/24/2026 14:46 Changes: 03/24/2026 14:46 (56) Complete: 🔍 Cache ID: 99:A14:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸