Mozilla released an important security update for Firefox, addressing a high-severity vulnerability that could lead to exploitable memory corruption. 

The patch fixes a race condition in the browser’s HTTP transaction handling component that security researchers warn attackers could use to compromise affected systems.

The security flaw, tracked as CVE-2025-3608, exists in Firefox’s nsHttpTransaction component, which is responsible for handling HTTP network transactions between the browser and web servers. 

CVE-2025-3608: Race condition in nsHttpTransaction 

According to Mozilla’s security advisory, this race condition vulnerability could be exploited to cause memory corruption, potentially creating an exploitable condition that might allow attackers to execute arbitrary code.

Race conditions occur when multiple processes or threads access and manipulate shared data concurrently, potentially leading to unpredictable behavior when the timing of operations becomes critical. 

In Firefox’s case, the race condition in nsHttpTransaction could lead to memory being accessed after it has been freed or modified while still in use by another process.

Security researchers have assigned this vulnerability a CVSS 3.0 base score of 8.1, categorizing it as high-severity with the vector CVSS:3.0. 

This indicates that while the vulnerability requires certain complex conditions to exploit (AC: H), it requires no privileges (PR: N) or user interaction (UI:N) and could potentially lead to a complete compromise of confidentiality, integrity, and availability if successfully exploited.

Mozilla’s internal Fuzzing Team discovered the vulnerability. This team specializes in automated testing techniques for uncovering software bugs. 

Fuzzing involves providing random or unexpected inputs to applications to identify potential weaknesses or security issues.

Mozilla’s browser fuzzing operations primarily utilize the Grizzly framework and tools like Domino to systematically test browser components for vulnerabilities. 

This proactive security approach has proven effective at identifying potentially exploitable conditions before malicious actors can discover them.

Risk FactorsDetailsAffected ProductsFirefox < 137.0.2ImpactAllows memory corruption, potentially creating an exploitable condition that might allow attackers to execute arbitrary code.Exploit PrerequisitesRequires race condition in nsHttpTransaction; no user interaction or privileges requiredCVSS 3.1 Score8.1 (High) Recommendations for Users Users are strongly advised to update to Firefox 137.0.2 immediately to mitigate the risk of exploitation.  The update is available across all supported operating systems. To verify your Firefox version, click on the menu button, select “Help,” and then “About Firefox.” As this vulnerability doesn’t require user interaction to exploit, prompt patching is particularly important for security.  Organizations using Firefox in enterprise environments should prioritize this update as part of their regular security maintenance procedures. The Mozilla Foundation continues to encourage security researchers to report vulnerabilities through their bug bounty program, which has proven effective at identifying and addressing potential security issues before they can be exploited in the wild. Malware Trends Report Based on 15000 SOC Teams Incidents, Q1 2025 out!-> Get Your Free Copy