CVE-2025-14321

CRITICAL

Firefox < 146.0 and 140.6-140.* - Use-After-Free in WebRTC Signaling

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2025-14321. PoCs published by h3raklez.

AI-analyzed exploit summary This repository contains a proof-of-concept exploit for CVE-2025-14321, a Use-After-Free (UAF) vulnerability in Firefox's WebRTC Encoded Transforms API. The exploit demonstrates heap corruption via dangling pointers in ArrayBuffers, leading to a tab crash in vulnerable Firefox versions.

Description

Use-after-free in the WebRTC: Signaling component. This vulnerability was fixed in Firefox 146, Firefox ESR 140.6, Thunderbird 146, and Thunderbird 140.6.

Exploits (1)

nomisec WORKING POC 2 stars
by h3raklez · poc
https://github.com/h3raklez/CVE-2025-14321

This repository contains a proof-of-concept exploit for CVE-2025-14321, a Use-After-Free (UAF) vulnerability in Firefox's WebRTC Encoded Transforms API. The exploit demonstrates heap corruption via dangling pointers in ArrayBuffers, leading to a tab crash in vulnerable Firefox versions.

Classification
Working Poc 100%
Attack Type
Rce
Complexity
Moderate
Reliability
Reliable
Target: Mozilla Firefox < 146, Firefox ESR < 140.6
No auth needed
Prerequisites: Firefox with specific about:config settings · WebRTC Encoded Transforms enabled · HTTP server to serve the PoC
devstral-2 · analyzed Feb 16, 2026 Full analysis →

References (5)

Core 5

Scores

CVSS v3 9.8
EPSS 0.0050
EPSS Percentile 38.5%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact total

Details

CWE
CWE-416
Status published
Products (8)
mozilla/firefox < 140.6.0
mozilla/firefox < 146.0
Mozilla/Firefox 140.6 - 140.*
Mozilla/Firefox 146
mozilla/thunderbird < 140.6.0
mozilla/thunderbird < 146.0
Mozilla/Thunderbird 140.6 - 140.*
Mozilla/Thunderbird 146
Published Dec 09, 2025
Tracked Since Feb 18, 2026