CVE-2026-5735 | Mozilla Firefox up to 149.0.1 memory corruption

VDB-355741 · CVE-2026-5735 · GCVE-0-2026-5735 MOZILLA FIREFOX UP TO 149.0.1 MEMORY CORRUPTION HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 6.0 $5k-$25k 1.88+ Summaryinfo A vulnerability, which was classified as critical, has been found in Mozilla Firefox up to 149.0.1. Affected by this issue is some unknown functionality. This manipulation causes memory corruption. This vulnerability is handled as CVE-2026-5735. The attack can be initiated remotely. There is not any exploit available. It is advisable to upgrade the affected component. Detailsinfo A vulnerability was found in Mozilla Firefox up to 149.0.1. It has been declared as critical. Affected by this vulnerability is an unknown functionality. The manipulation with an unknown input leads to a memory corruption vulnerability. The CWE definition for the vulnerability is CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is: Memory safety bugs present in Firefox 149.0.1 and Thunderbird 149.0.1. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 149.0.2. The advisory is shared at bugzilla.mozilla.org. This vulnerability is known as CVE-2026-5735 since 04/07/2026. 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 $5k-$25k at the moment (estimation calculated on 04/07/2026). Upgrading to version 149.0.2 eliminates this vulnerability. Productinfo Type Web Browser Vendor Mozilla Name Firefox Version 149.0.0 149.0.1 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: Memory corruption CWE: 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 149.0.2 Timelineinfo 04/07/2026 Advisory disclosed 04/07/2026 +0 days CVE reserved 04/07/2026 +0 days VulDB entry created 04/07/2026 +0 days VulDB entry last update Sourcesinfo Vendor: mozilla.org Product: mozilla.org Advisory: bugzilla.mozilla.org Status: Confirmed CVE: CVE-2026-5735 (🔒) GCVE (CVE): GCVE-0-2026-5735 GCVE (VulDB): GCVE-100-355741 Entryinfo Created: 04/07/2026 15:28 Changes: 04/07/2026 15:28 (55) Complete: 🔍 Cache ID: 99:7DC:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸