Skip to main content

Mozilla Firefox CVE-2026-12326

| EUVDEUVD-2026-37072 HIGH
Buffer Overflow (CWE-119)
2026-06-16 mozilla GHSA-jg8p-vfvp-34jw
Mozilla Buffer Overflow RCE
8.1
CVSS 3.1 · Vendor: mozilla
Share

Severity by source

Vendor (mozilla) PRIMARY
8.1 HIGH
AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
vuln.today AI
7.5 HIGH

Network-delivered content bug needing victim to load malicious content (UI:R) and significant effort to weaponize (AC:H); no privileges needed, full RCE impact.

3.1 AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
4.0 AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
SUSE
CRITICAL
qualitative
Red Hat
7.5 HIGH
qualitative

Primary rating from Vendor (mozilla).

CVSS VectorVendor: mozilla

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Lifecycle Timeline

3
Analysis Generated
Jun 30, 2026 - 05:29 vuln.today
CVSS changed
Jun 30, 2026 - 03:24 NVD
7.3 (HIGH) 8.1 (HIGH)
CVE Published
Jun 16, 2026 - 11:52 cve.org
UNKNOWN (no severity yet)

DescriptionCVE.org

Memory safety bugs present in Firefox 151 and Thunderbird 151. 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 152.

Articles & Coverage 1

News 5 New Mozilla Vulnerabilities - 5 High Severity, No Public POC Jun 16, 2026

AnalysisAI

Memory corruption in Mozilla Firefox 151 and Thunderbird 151 may allow remote attackers to achieve arbitrary code execution when a victim renders malicious web content, per Mozilla advisory MFSA2026-60. The flaw stems from multiple memory safety bugs that Mozilla assessed as potentially exploitable, though no public exploit identified at time of analysis and EPSS exploitation probability is low (0.22%, 13th percentile). It is fixed in Firefox 152, with no special privileges required but high attack complexity per the CVSS vector.

Technical ContextAI

This is a rollup of multiple internally-discovered memory safety defects in Mozilla's Gecko browser engine, which underlies both the Firefox browser and the Thunderbird mail client (Thunderbird renders message content using the same engine). The root cause class is CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer), tagged as Buffer Overflow, meaning the engine reads or writes outside allocated buffer bounds while parsing or processing untrusted content. The CPE cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* confirms the Firefox application is affected; the description and Mozilla advisory extend the same engine-level bugs to Thunderbird 151. Because these are batch-reported memory safety issues (dozens of Bugzilla IDs referenced), they were caught proactively rather than tied to a single proven exploit primitive.

RemediationAI

Vendor-released patch: Firefox 152 - upgrade Firefox to version 152 or later, and update Thunderbird to the corresponding fixed release per Mozilla advisory MFSA2026-60 (https://www.mozilla.org/security/advisories/mfsa2026-60/) and MFSA2026-57 (https://www.mozilla.org/security/advisories/mfsa2026-57/). Linux users on Red Hat-based distributions should apply the vendor RPM updates referenced in the Red Hat VEX (https://access.redhat.com/security/cve/CVE-2026-12326). As an interim compensating control until patching, you can reduce attack surface by enabling Firefox's stricter content/JavaScript settings or deploying it in a sandboxed/least-privilege profile, and for Thunderbird keep remote content blocking enabled so messages do not auto-load attacker-controlled content (trade-off: some pages and HTML mail may render incompletely). These mitigations reduce but do not eliminate exposure, so prompt upgrade to the fixed version remains the primary fix.

More in Mozilla

View all
CVE-2015-4495 HIGH POC
8.8 Aug 08

The PDF reader in Mozilla Firefox before 39.0.3, Firefox ESR 38.x before 38.1.1, and Firefox OS before 2.2 allows remote
CVE-2013-1690 HIGH POC
8.8 Jun 26

Mozilla Firefox before 22.0, Firefox ESR 17.x before 17.0.7, Thunderbird before 17.0.7, and Thunderbird ESR 17.x before

CVE-2013-0758 CRITICAL POC
9.3 Jan 13

Mozilla Firefox before 18.0, Firefox ESR 10.x before 10.0.12 and 17.x before 17.0.2, Thunderbird before 17.0.2, Thunderb
CVE-2013-0753 CRITICAL POC
9.3 Jan 13

Use-after-free vulnerability in the serializeToStream implementation in the XMLSerializer component in Mozilla Firefox b
CVE-2012-3993 CRITICAL POC
9.3 Oct 10

The Chrome Object Wrapper (COW) implementation in Mozilla Firefox before 16.0, Firefox ESR 10.x before 10.0.8, Thunderbi
CVE-2013-1710 CRITICAL POC
10.0 Aug 07

The crypto.generateCRMFRequest function in Mozilla Firefox before 23.0, Firefox ESR 17.x before 17.0.8, Thunderbird befo
CVE-2017-3823 HIGH POC
8.8 Feb 01

An issue was discovered in the Cisco WebEx Extension before 1.0.7 on Google Chrome, the ActiveTouch General Plugin Conta
CVE-2014-8636 HIGH POC
7.5 Jan 14

The XrayWrapper implementation in Mozilla Firefox before 35.0 and SeaMonkey before 2.32 does not properly interact with

CVE-2013-0757 CRITICAL POC
9.3 Jan 13

The Chrome Object Wrapper (COW) implementation in Mozilla Firefox before 18.0, Firefox ESR 17.x before 17.0.2, Thunderbi
CVE-2014-1510 CRITICAL POC
9.8 Mar 19

The Web IDL implementation in Mozilla Firefox before 28.0, Firefox ESR 24.x before 24.4, Thunderbird before 24.4, and Se
CVE-2014-1511 CRITICAL POC
9.8 Mar 19

Mozilla Firefox before 28.0, Firefox ESR 24.x before 24.4, Thunderbird before 24.4, and SeaMonkey before 2.25 allow remo
CVE-2013-0643 HIGH
8.8 Feb 27

The Firefox sandbox in Adobe Flash Player before 10.3.183.67 and 11.x before 11.6.602.171 on Windows and Mac OS X, and b

Same weakness CWE-119 – Buffer Overflow

View all
CVE-2017-11882 HIGH POC
7.8
CVE-2014-6332 HIGH POC
8.8
CVE-2015-2426 HIGH POC
8.8
CVE-2013-3918 HIGH POC
8.8
CVE-2023-4966 HIGH POC
7.5
CVE-2017-11774 HIGH POC
7.8
CVE-2013-3660 HIGH POC
7.8
CVE-2017-6736 HIGH POC
8.8

Same technique Buffer Overflow

View all
CVE-2017-7269 CRITICAL POC
9.8
CVE-2015-5119 CRITICAL POC
9.8
CVE-2015-3113 CRITICAL POC
9.8
CVE-2011-2462 CRITICAL POC
9.8
CVE-2009-0927 HIGH POC
8.8
CVE-2012-1889 HIGH POC
8.8
CVE-2017-11882 HIGH POC
7.8
CVE-2010-3333 HIGH POC
7.8

Vendor StatusVendor

SUSE

Severity: Critical
Product Status
openSUSE Tumbleweed Fixed
SUSE Linux Enterprise Desktop 15 SP7 Affected
SUSE Linux Enterprise Desktop 15 SP7 Affected
SUSE Linux Enterprise High Performance Computing 15 SP7 Affected
SUSE Linux Enterprise Module for Desktop Applications 15 SP7 Affected

Share

CVE-2026-12326 vulnerability details – vuln.today
Back

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy