Mozilla Firefox up to 147 HTML Remote Code Execution

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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8.5$0-$5k0.00

Summaryinfo

A vulnerability described as critical has been identified in Mozilla Firefox up to 147. The affected element is an unknown function of the component HTML Component. The manipulation results in Remote Code Execution. This vulnerability is reported as CVE-2026-2771. The attack can be launched remotely. No exploit exists. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability classified as critical has been found in Mozilla Firefox up to 147. Affected is an unknown code block of the component HTML Component. The manipulation with an unknown input leads to a remote code execution vulnerability. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

Undefined behavior in the DOM: Core & HTML component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.

The advisory is available at bugzilla.mozilla.org. This vulnerability is traded as CVE-2026-2771 since 02/19/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Successful exploitation requires user interaction by the victim. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 03/11/2026).

The vulnerability scanner Nessus provides a plugin with the ID 299906 (Linux Distros Unpatched Vulnerability : CVE-2026-2771), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 148 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (299906) and CERT Bund (WID-SEC-2026-0497). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

  • Debian Linux
  • Red Hat Enterprise Linux
  • SUSE Linux
  • Oracle Linux
  • IGEL OS
  • SUSE openSUSE
  • RESF Rocky Linux
  • Mozilla Firefox
  • Mozilla Firefox ESR
  • Mozilla Thunderbird

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.6
VulDB Meta Temp Score: 8.5

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 9.8
NVD Vector: 🔒

ADP CISA Base Score: 9.8
ADP CISA Vector: 🔒

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Remote Code Execution
CWE: Unknown
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 299906
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-2771

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Firefox 148

Timelineinfo

02/19/2026 CVE reserved
02/24/2026 +5 days Advisory disclosed
02/24/2026 +0 days VulDB entry created
03/11/2026 +15 days VulDB entry last update

Sourcesinfo

Vendor: mozilla.org
Product: mozilla.org

Advisory: bugzilla.mozilla.org
Status: Confirmed

CVE: CVE-2026-2771 (🔒)
GCVE (CVE): GCVE-0-2026-2771
GCVE (VulDB): GCVE-100-347562
CERT Bund: WID-SEC-2026-0497 - Mozilla Firefox, Firefox ESR und Thunderbird: Mehrere Schwachstellen

Entryinfo

Created: 02/24/2026 16:07
Updated: 03/11/2026 20:21
Changes: 02/24/2026 16:07 (54), 02/25/2026 13:22 (2), 03/02/2026 12:28 (7), 03/03/2026 18:54 (1), 03/11/2026 20:21 (22)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Discussion

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