Mozilla Firefox up to 149 memory corruption

CVSS Meta Temp Score
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CTI Interest Score
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6.7$5k-$25k0.00

Summaryinfo

A vulnerability, which was classified as critical, was found in Mozilla Firefox up to 149. Affected by this issue is some unknown functionality. The manipulation results in memory corruption. This vulnerability was named CVE-2026-6784. The attack may be performed from remote. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Mozilla Firefox up to 149. It has been classified as critical. Affected is some unknown functionality. The manipulation with an unknown input leads to a memory corruption vulnerability. CWE is classifying the issue as CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

Memory safety bugs present in Firefox 149 and Thunderbird 149. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 150 and Thunderbird 150.

This vulnerability is traded as CVE-2026-6784 since 04/21/2026. 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 $5k-$25k at the moment (estimation calculated on 07/02/2026).

The vulnerability scanner Nessus provides a plugin with the ID 307899 (Mozilla Firefox < 150.0), 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 (307899) and CERT Bund (WID-SEC-2026-1228). 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
  • 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: 6.9
VulDB Meta Temp Score: 6.7

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

ADP CISA Base Score: 7.5
ADP CISA Vector: 🔒

CVSSv2info

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

Exploitinginfo

Class: Memory corruption
CWE: CWE-119
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: 307899
Nessus Name: Mozilla Firefox < 150.0

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
07/02/2026 +72 days VulDB entry last update

Sourcesinfo

Vendor: mozilla.org
Product: mozilla.org

Status: Confirmed

CVE: CVE-2026-6784 (🔒)
GCVE (CVE): GCVE-0-2026-6784
GCVE (VulDB): GCVE-100-358458
CERT Bund: WID-SEC-2026-1228 - Mozilla Thunderbird, Firefox ESR und Firefox: Mehrere Schwachstellen

Entryinfo

Created: 04/21/2026 16:00
Updated: 07/02/2026 08:42
Changes: 04/21/2026 16:00 (54), 04/21/2026 20:03 (2), 05/21/2026 02:41 (7), 07/02/2026 08:42 (12)
Complete: 🔍
Cache ID: 216::103

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

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