Cyber Posture

CVE-2026-6770

Medium

Published: 21 April 2026

Published
21 April 2026
Modified
22 April 2026
KEV Added
Patch
CVSS Score 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L
EPSS Score 0.0006 18.0th percentile
Risk Priority 13 60% EPSS · 20% KEV · 20% CVSS

Description

Other issue in the Storage: IndexedDB component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.

Likely Mitigating ControlsAI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-200

Automated marking applies security attributes to system outputs, making it harder for attackers to exploit unmarked sensitive information leading to unauthorized exposure.

addresses: CWE-200

Proper attribute retention and permitted-value enforcement limits unauthorized actors from accessing sensitive information lacking correct labels.

addresses: CWE-200

Prevents unauthorized exposure of sensitive information by prohibiting untrusted external systems from processing or storing it.

addresses: CWE-200

By enforcing authorization matching prior to sharing, the control reduces the risk of exposing sensitive information to unauthorized actors.

addresses: CWE-200

Review and removal of nonpublic information from publicly accessible systems directly prevents exposure of sensitive data to unauthorized actors.

addresses: CWE-200

Data mining protection mechanisms detect and block unauthorized bulk extraction of sensitive data, directly mitigating exposure to unauthorized actors.

addresses: CWE-200

Literacy training teaches users to recognize and avoid actions that result in unauthorized exposure of sensitive information.

addresses: CWE-200

Retaining and monitoring training records confirms personnel have completed privacy and security awareness training on handling sensitive data, reducing the chance of unauthorized exposure due to lack of knowledge.

Security SummaryAI

CVE-2026-6770 is an unspecified issue in the Storage: IndexedDB component of Mozilla Firefox and Thunderbird products. Published on 2026-04-21, it carries a CVSS v3.1 base score of 6.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L) and is associated with CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor). The vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.

Remote attackers require no privileges or user interaction to exploit this network-accessible vulnerability. Successful exploitation could result in low-impact confidentiality loss, such as exposure of sensitive information, and low-impact availability disruption.

Mozilla's security advisories MFSA2026-30, MFSA2026-32, MFSA2026-33, and MFSA2026-34, along with Bugzilla entry 2024220, detail the issue. Mitigation requires updating to the patched releases: Firefox 150 or later, Firefox ESR 140.10 or later, Thunderbird 150 or later, or Thunderbird 140.10 or later.

Details

CWE(s)

Affected Products

mozilla
firefox
≤ 140.10.0 · ≤ 150.0
mozilla
thunderbird
≤ 140.10.0

MITRE ATT&CK Enterprise TechniquesAI

T1005 Data from Local System Collection
Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.
Why these techniques?

IndexedDB storage component vulnerability directly enables unauthorized local data access and sensitive information exposure (CWE-200) from the client system without authentication or interaction.

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

References