Cyber Posture

CVE-2026-2794

High

Published: 24 February 2026

Published
24 February 2026
Modified
13 April 2026
KEV Added
Patch
CVSS Score 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS Score 0.0004 13.6th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-2794 is a high-severity Use of Uninitialized Resource (CWE-908) vulnerability in Mozilla Firefox. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Browser Session Hijacking (T1185); ranked at the 13.6th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SI-16 (Memory Protection) and SI-2 (Flaw Remediation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Browser Session Hijacking (T1185) and 2 other techniques. What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

prevent

Directly mitigates the uninitialized memory disclosure by requiring timely patching to Firefox version 148 or later where the flaw is remediated.

prevent

Implements memory protection mechanisms that prevent unauthorized disclosure of sensitive data from uninitialized memory regions exploited in this CVE.

detect

Enables detection of the specific vulnerability in deployed Firefox instances through regular scanning, prompting remediation.

MITRE ATT&CK Enterprise TechniquesAI

T1185 Browser Session Hijacking Collection
Adversaries may take advantage of security vulnerabilities and inherent functionality in browser software to change content, modify user-behaviors, and intercept information as part of various browser session hijacking techniques.
T1539 Steal Web Session Cookie Credential Access
An adversary may steal web application or service session cookies and use them to gain access to web applications or Internet services as an authenticated user without needing credentials.
T1555.003 Credentials from Web Browsers Credential Access
Adversaries may acquire credentials from web browsers by reading files specific to the target browser.
Why these techniques?

Uninitialized memory disclosure in browser process directly enables reading of in-memory sensitive data such as session cookies, auth tokens and credentials, facilitating browser session hijacking, web session cookie theft and credential harvesting from browsers.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v18.1

NVD Description

Information disclosure due to uninitialized memory in Firefox and Firefox Focus for Android. This vulnerability was fixed in Firefox 148.

Deeper analysisAI

CVE-2026-2794 is an information disclosure vulnerability stemming from uninitialized memory, classified under CWE-908. It affects Firefox and Firefox Focus for Android browsers. The issue was addressed in Firefox version 148, with the CVE published on 2026-02-24.

The vulnerability carries a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N), indicating it is exploitable remotely over the network with low complexity, no required privileges, and no user interaction. Attackers can achieve high-impact confidentiality violations, such as leaking sensitive data from memory, while integrity and availability remain unaffected.

Mozilla's security advisory MFSA2026-13 and Bugzilla bug 2008365 provide further details on the flaw. Mitigation requires updating to Firefox 148 or later versions where the vulnerability has been patched.

Details

CWE(s)

Affected Products

mozilla
firefox
≤ 148.0

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References