Mozilla Firefox up to 149 Playback Remote Code Execution

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.0$0-$5k0.00

Summaryinfo

A vulnerability was found in Mozilla Firefox up to 149. It has been classified as critical. The impacted element is an unknown function of the component Playback. The manipulation leads to an unknown weakness. This vulnerability is referenced as CVE-2026-6778. Remote exploitation of the attack is possible. No exploit is available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Mozilla Firefox up to 149 and classified as critical. This issue affects an unknown code block of the component Playback. The impact remains unknown. The summary by CVE is:

Invalid pointer in the Audio/Video: Playback component. This vulnerability was fixed in Firefox 150.

It is possible to read the advisory at bugzilla.mozilla.org. The identification of this vulnerability is CVE-2026-6778 since 04/21/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. It demands that the victim is doing some kind of user interaction. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 05/21/2026).

The vulnerability scanner Nessus provides a plugin with the ID 310611 (Linux Distros Unpatched Vulnerability : CVE-2026-6778), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 150 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (310611) and CERT Bund (WID-SEC-2026-1228). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

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

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.3
VulDB Meta Temp Score: 6.0

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

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
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: 310611
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-6778

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Firefox 150

Timelineinfo

04/21/2026 Advisory disclosed
04/21/2026 +0 days CVE reserved
04/21/2026 +0 days VulDB entry created
05/21/2026 +29 days VulDB entry last update

Sourcesinfo

Vendor: mozilla.org
Product: mozilla.org

Advisory: bugzilla.mozilla.org
Status: Confirmed

CVE: CVE-2026-6778 (🔒)
GCVE (CVE): GCVE-0-2026-6778
GCVE (VulDB): GCVE-100-358475
CERT Bund: WID-SEC-2026-1228 - Mozilla Thunderbird, Firefox ESR und Firefox: Mehrere Schwachstellen

Entryinfo

Created: 04/21/2026 16:05
Updated: 05/21/2026 00:06
Changes: 04/21/2026 16:05 (54), 04/28/2026 19:09 (2), 05/21/2026 00:06 (7)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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