High

Incorrect boundary conditions in Firefox/Thunderbird Audio/Video component

IdentifiersCVE-2026-4714CWE-119

CVE-2026-4714 is a memory-safety vulnerability described as incorrect boundary conditions in the Audio/Video component of Mozilla Firefox and Thunderbird. The issue affects Firefox before 149, Firefox ESR before 140.9, Thunderbird before 149, and Thunderbird before 140.9. Based on the available description, the flaw arises from improper handling of bounds in audio/video processing logic, which can lead to out-of-bounds memory access during parsing or processing of crafted media content. No vulnerable function or code path is provided in the supplied content.

For your environment

Are you exposed to this one?

Mallory correlates every CVE against your assets, your vendors, and active adversary campaigns. Know which vulnerabilities matter for you, not just which ones are loud.

Start free trial

ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

The supplied context indicates this issue is among multiple Thunderbird/Firefox security issues that could result in arbitrary code execution or information disclosure. Given the boundary-condition nature of the flaw in a media-processing component, successful exploitation could plausibly cause memory corruption, application instability, process compromise, or exposure of sensitive memory contents. The precise impact for this specific CVE is not further specified in the provided content.

Mitigation

If you can’t patch tonight, do this now.

If immediate patching is not possible, reduce exposure by limiting use of untrusted or attacker-supplied audio/video content and untrusted web/email content that could trigger the vulnerable media-processing path. In enterprise environments, consider restricting access to untrusted sites and disabling or isolating workflows that process untrusted media until updates can be applied. The provided content does not include any vendor-specific workaround.

Remediation

Patch, then assume compromise.

Upgrade affected products to a fixed version: Firefox 149 or later, Firefox ESR 140.9 or later, Thunderbird 149 or later, or Thunderbird 140.9 or later. No more specific vendor remediation details are provided in the supplied content.

PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType

MozillaFirefoxapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

11 sources tracked across advisories and community write-ups. News coverage will land here when it surfaces.

11 SOURCESView more in app

No news coverage yet. Advisories and community discussion only.

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.

Start free trial

Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity4