CVE-2025-14861 Overview
CVE-2025-14861 affects Mozilla Firefox 146 through memory safety bugs identified by Mozilla developers and the community. Several of these bugs showed evidence of memory corruption. Mozilla presumes that with sufficient effort, some of these issues could be exploited to run arbitrary code. The vulnerability is classified under [CWE-119] (Improper Restriction of Operations within the Bounds of a Memory Buffer). Mozilla resolved the issue in Firefox 146.0.1.
Critical Impact
Successful exploitation can lead to arbitrary code execution within the browser process, compromising confidentiality, integrity, and availability of affected systems.
Affected Products
- Mozilla Firefox 146
- Firefox releases prior to 146.0.1
- Desktop platforms running vulnerable Firefox builds
Discovery Timeline
- 2025-12-18 - CVE-2025-14861 published to NVD
- 2026-04-13 - Last updated in NVD database
Technical Details for CVE-2025-14861
Vulnerability Analysis
The advisory groups multiple memory safety defects discovered in Firefox 146. Mozilla tracks the underlying bugs as 1996570 and 1999700 in Bugzilla. The defects align with [CWE-119], indicating operations performed outside the intended bounds of a memory buffer. Such conditions commonly include out-of-bounds reads, out-of-bounds writes, and use-after-free patterns in browser components.
Mozilla states that some bugs showed evidence of memory corruption. Memory corruption in a renderer or content process can disrupt control-flow integrity and influence object layout. Attackers chaining such primitives with sandbox or JIT weaknesses can achieve code execution within the browser context.
Root Cause
The root cause lies in unsafe memory handling in components shipped with Firefox 146. Specific defects are tracked privately in Mozilla's bug tracker pending broader patch adoption. Mozilla addressed the bugs in Firefox 146.0.1 through corrected bounds checks and lifecycle handling.
Attack Vector
Exploitation requires a user to load attacker-controlled web content in a vulnerable Firefox build. The attack vector is network-based and requires user interaction, such as visiting a malicious page or rendering hostile content embedded in a trusted site. No authentication is required to deliver the payload. Refer to the Mozilla Security Advisory MFSA-2025-98 and the Mozilla Bug List for technical details.
Detection Methods for CVE-2025-14861
Indicators of Compromise
- Unexpected Firefox process crashes or renderer tab failures correlated with browsing activity
- Child firefox.exe or plugin-container processes spawning shells, scripting hosts, or LOLBins
- Outbound connections from Firefox processes to recently registered or low-reputation domains
Detection Strategies
- Inventory installed Firefox versions across endpoints and flag any build earlier than 146.0.1
- Hunt for browser process anomalies, including memory access violations and unexpected module loads
- Correlate web proxy logs with endpoint telemetry to identify users visiting suspicious URLs prior to crashes
Monitoring Recommendations
- Forward Firefox crash reports and EDR process telemetry to a centralized analytics platform
- Alert on Firefox child processes executing cmd.exe, powershell.exe, wscript.exe, or bash
- Track outbound network connections initiated by browser processes outside of normal browsing patterns
How to Mitigate CVE-2025-14861
Immediate Actions Required
- Upgrade all Firefox installations to version 146.0.1 or later without delay
- Validate enterprise update channels and managed deployment tools are pushing the fixed build
- Restart browser sessions after patching to ensure vulnerable processes terminate
Patch Information
Mozilla released Firefox 146.0.1 to remediate the memory safety defects. Administrators should consult the Mozilla Security Advisory MFSA-2025-98 for full patch details and apply updates through standard Firefox update mechanisms or enterprise deployment tooling.
Workarounds
- Restrict browsing to trusted sites until the patch is deployed across the fleet
- Enable strict content blocking and disable JavaScript on untrusted origins where feasible
- Apply application allowlisting to block child process execution from Firefox binaries
# Verify installed Firefox version on Linux/macOS
firefox --version
# Windows: query installed version via registry
reg query "HKLM\SOFTWARE\Mozilla\Mozilla Firefox" /v CurrentVersion
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
