Mozilla Firefox up to 140.11 memory corruption

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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5.7$5k-$25k0.00

Summaryinfo

A vulnerability labeled as critical has been found in Mozilla Firefox up to 140.11. Impacted is an unknown function. Executing a manipulation can lead to memory corruption. This vulnerability is tracked as CVE-2026-12329. The attack can be launched remotely. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as critical was found in Mozilla Firefox up to 140.11. This vulnerability affects an unknown part. 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:

Memory safety bug fixed in Thunderbird ESR 140.12. This vulnerability was fixed in Firefox ESR 140.12 and Thunderbird 140.12.

The advisory is shared for download at bugzilla.mozilla.org. This vulnerability was named CVE-2026-12329 since 06/15/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 07/10/2026).

The vulnerability scanner Nessus provides a plugin with the ID 321490 (Debian dsa-6350 : firefox-esr - security update), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 140.12 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (321490) and CERT Bund (WID-SEC-2026-1959). Once again VulDB remains the best source for vulnerability data.

Affected

  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu 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: 5.8
VulDB Meta Temp Score: 5.7

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

ADP CISA Base Score: 5.3
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: 321490
Nessus Name: Debian dsa-6350 : firefox-esr - security update

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Firefox 140.12

Timelineinfo

06/15/2026 CVE reserved
06/16/2026 +1 days Advisory disclosed
06/16/2026 +0 days VulDB entry created
07/10/2026 +24 days VulDB entry last update

Sourcesinfo

Vendor: mozilla.org
Product: mozilla.org

Advisory: bugzilla.mozilla.org
Status: Confirmed

CVE: CVE-2026-12329 (🔒)
GCVE (CVE): GCVE-0-2026-12329
GCVE (VulDB): GCVE-100-371332
CERT Bund: WID-SEC-2026-1959 - Mozilla Firefox, Firefox ESR und Thunderbird: Mehrere Schwachstellen

Entryinfo

Created: 06/16/2026 16:31
Updated: 07/10/2026 06:45
Changes: 06/16/2026 16:31 (55), 06/19/2026 05:17 (2), 06/20/2026 12:47 (7), 07/03/2026 03:53 (12), 07/10/2026 06:45 (1)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

Discussion

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