Mozilla Firefox up to 149 WebAssembly 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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6.0$0-$5k0.00

Summaryinfo

A vulnerability identified as critical has been detected in Mozilla Firefox up to 149. Impacted is an unknown function of the component WebAssembly. The manipulation leads to an unknown weakness. This vulnerability is documented as CVE-2026-6757. The attack can be initiated remotely. There is not any exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Mozilla Firefox up to 149. It has been rated as critical. This issue affects some unknown functionality of the component WebAssembly. The impact remains unknown. The summary by CVE is:

Invalid pointer in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 150 and Firefox ESR 140.10.

It is possible to read the advisory at bugzilla.mozilla.org. The identification of this vulnerability is CVE-2026-6757 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 05/20/2026).

The vulnerability scanner Nessus provides a plugin with the ID 310182 (Debian dsa-6229 : thunderbird - security update), 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 (310182) 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: 310182
Nessus Name: Debian dsa-6229 : thunderbird - security update

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
05/20/2026 +29 days VulDB entry last update

Sourcesinfo

Vendor: mozilla.org
Product: mozilla.org

Advisory: bugzilla.mozilla.org
Status: Confirmed

CVE: CVE-2026-6757 (🔒)
GCVE (CVE): GCVE-0-2026-6757
GCVE (VulDB): GCVE-100-358451
CERT Bund: WID-SEC-2026-1228 - Mozilla Thunderbird, Firefox ESR und Firefox: Mehrere Schwachstellen

Entryinfo

Created: 04/21/2026 15:57
Updated: 05/20/2026 13:50
Changes: 04/21/2026 15:57 (54), 04/25/2026 10:39 (2), 05/20/2026 13:50 (7)
Complete: 🔍
Cache ID: 216::103

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

Discussion

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