Mozilla Firefox up to 115.39/140.14/153.1/154 memory corruption

CVSS Meta Temp Score
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CTI Interest Score
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7.2$5k-$25k0.34

Summaryinfo

A vulnerability was found in Mozilla Firefox up to 115.39/140.14/153.1/154 and classified as critical. Affected by this issue is some unknown functionality. Executing a manipulation can lead to memory corruption. This vulnerability appears as CVE-2026-84145. The attack may be performed from remote. There is no available exploit. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Mozilla Firefox up to 115.39/140.14/153.1/154. It has been declared as critical. This vulnerability affects an unknown code. The manipulation with an unknown input leads to a memory corruption vulnerability. The CWE definition for the vulnerability is 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. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

Internally found bugs present in Thunderbird 154, Thunderbird ESR 153.1 and Thunderbird ESR 140.14. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.

The advisory is available at bugzilla.mozilla.org. This vulnerability was named CVE-2026-84145 since 09/01/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. 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 09/23/2026).

The vulnerability scanner Nessus provides a plugin with the ID 342302 (Linux Distros Unpatched Vulnerability : CVE-2026-84145), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 115.40, 140.15, 153.2 or 155 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (342302) and CERT Bund (WID-SEC-2026-3132). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

  • Debian Linux
  • Red Hat Enterprise Linux
  • IGEL OS
  • SUSE Linux
  • SUSE openSUSE
  • Oracle 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: 7.4
VulDB Meta Temp Score: 7.2

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
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: 342302
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-84145

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Firefox 115.40/140.15/153.2/155

Timelineinfo

09/01/2026 Advisory disclosed
09/01/2026 +0 days CVE reserved
09/01/2026 +0 days VulDB entry created
09/23/2026 +22 days VulDB entry last update

Sourcesinfo

Vendor: mozilla.org
Product: mozilla.org

Advisory: bugzilla.mozilla.org
Status: Confirmed

CVE: CVE-2026-84145 (🔒)
GCVE (CVE): GCVE-0-2026-84145
GCVE (VulDB): GCVE-100-397618
CERT Bund: WID-SEC-2026-3132 - Mozilla Firefox und Thunderbird: Mehrere Schwachstellen

Entryinfo

Created: 09/01/2026 15:10
Updated: 09/23/2026 11:56
Changes: 09/01/2026 15:10 (56), 09/03/2026 02:18 (2), 09/07/2026 06:44 (12), 09/08/2026 10:41 (7), 09/23/2026 11:56 (1)
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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