CVE-2026-4706 - Vulnerability Details

- Incorrect boundary conditions in the Graphics: Canvas2D component

Description

Incorrect boundary conditions in the Graphics: Canvas2D component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

Published: 2026-03-24

Score: 7.5 High

EPSS: < 1% Very Low

KEV: No

Impact:

Action:

Analysis

Impact

This vulnerability involves incorrect boundary checks in the Canvas2D graphics component, potentially allowing out‑of‑bounds memory reads or writes. The resulting memory corruption can cause stability issues or other unintended behavior within Firefox or Thunderbird.

Affected Systems

Mozilla Firefox and Thunderbird, including the extended support releases. All versions prior to Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9 are affected.

Risk and Exploitability

The CVSS base score of 7.5 indicates high severity. The EPSS score is below 1 %, implying low exploitation likelihood so far. The vulnerability is not listed in the CISA KEV catalog. The description does not specify an attack vector; it is inferred that malicious web content or media that feeds into the Canvas2D component could potentially trigger the flaw.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Mozilla

Firefox

affected

Version	Status	Constraints
`115.34`	unaffected	≤ 115.*
`140.9`	unaffected	≤ 140.*
`149`	unaffected	≤ *

Mozilla

Thunderbird

affected

Version	Status	Constraints
`140.9`	unaffected	≤ 140.*
`149`	unaffected	≤ *

Configuration 1 [-]

OR	cpe:2.3:a:mozilla:firefox:::::esr:::*
	cpe:2.3:a:mozilla:firefox:::::-:::*
	cpe:2.3:a:mozilla:firefox:::::esr:::*

No data.

Vendor Product Confidence Versions

Mozilla

Firefox

100%

Version	Status	Scheme	Platform
`[0,149)`	affected	generic	—

Mozilla

Firefox Esr

100%

Version	Status	Scheme	Platform
`[0,115.34)`	affected	generic	—

Mozilla

Firefox Esr

100%

Version	Status	Scheme	Platform
`[0,140.9)`	affected	generic	—

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Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

Update Firefox to version 149 or newer, or to Firefox ESR 115.34 or 140.9.
Update Thunderbird to version 149 or newer, or to Thunderbird ESR 140.9.
If an update is not immediately available, monitor Mozilla security advisories and apply patches as soon as they are released.

Generated by OpenCVE AI on April 13, 2026 at 16:39 UTC.

Tracking

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Advisories

Source	ID	Title
Debian DLA	DLA-4510-1	firefox-esr security update
Debian DLA	DLA-4511-1	thunderbird security update
Debian DSA	DSA-6178-1	firefox-esr security update
Debian DSA	DSA-6179-1	thunderbird security update

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00026.

Exploitation none

Automatable yes

Technical Impact partial

References

Link	Providers
https://bugzilla.mozilla.org/show_bug.cgi?id=2015091
https://nvd.nist.gov/vuln/detail/CVE-2026-4706
https://www.cve.org/CVERecord?id=CVE-2026-4706
https://www.mozilla.org/security/advisories/mfsa2026-20/
https://www.mozilla.org/security/advisories/mfsa2026-21/
https://www.mozilla.org/security/advisories/mfsa2026-22/
https://www.mozilla.org/security/advisories/mfsa2026-22/#CVE-2026-4706
https://www.mozilla.org/security/advisories/mfsa2026-23/
https://www.mozilla.org/security/advisories/mfsa2026-24/
https://www.mozilla.org/security/advisories/mfsa2026-24/#CVE-2026-4706

History

Mon, 13 Apr 2026 14:30:00 +0000

Type	Values Removed	Values Added
Description	Incorrect boundary conditions in the Graphics: Canvas2D component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9.	Incorrect boundary conditions in the Graphics: Canvas2D component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

Thu, 26 Mar 2026 00:15:00 +0000

Type	Values Removed	Values Added
Weaknesses		CWE-787
References		https://nvd.nist.gov/vuln/detail/CVE-2026-4706 https://www.cve.org/CVERecord?id=CVE-2026-4706 https://www.mozilla.org/security/advisories/mfsa2026-22/#CVE-2026-4706 https://www.mozilla.org/security/advisories/mfsa2026-24/#CVE-2026-4706
Metrics	threat_severity `None`	threat_severity `Moderate`

Wed, 25 Mar 2026 20:15:00 +0000

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Wed, 25 Mar 2026 12:00:00 +0000

Type	Values Removed	Values Added
First Time appeared		Mozilla firefox Esr
Vendors & Products		Mozilla firefox Esr

Tue, 24 Mar 2026 20:30:00 +0000

Type	Values Removed	Values Added
Description	Incorrect boundary conditions in the Graphics: Canvas2D component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, and Firefox ESR < 140.9.	Incorrect boundary conditions in the Graphics: Canvas2D component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9.
First Time appeared		Mozilla Mozilla firefox
Weaknesses		CWE-754
CPEs		cpe:2.3:a:mozilla:firefox:::::-:::* cpe:2.3:a:mozilla:firefox:::::esr:::*
Vendors & Products		Mozilla Mozilla firefox
References		https://www.mozilla.org/security/advisories/mfsa2026-23/ https://www.mozilla.org/security/advisories/mfsa2026-24/
Metrics		cvssV3_1 `{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}`

Tue, 24 Mar 2026 12:45:00 +0000

Type	Values Removed	Values Added
Description		Incorrect boundary conditions in the Graphics: Canvas2D component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, and Firefox ESR < 140.9.
Title		Incorrect boundary conditions in the Graphics: Canvas2D component
References		https://bugzilla.mozilla.org/show_bug.cgi?id=2015091 https://www.mozilla.org/security/advisories/mfsa2026-20/ https://www.mozilla.org/security/advisories/mfsa2026-21/ https://www.mozilla.org/security/advisories/mfsa2026-22/

Subscriptions

Mozilla Firefox Firefox Esr

MITRE

Status: PUBLISHED

Assigner: mozilla

Published: 2026-03-24T12:30:33.263Z

Updated: 2026-04-13T13:50:38.452Z

Reserved: 2026-03-23T23:22:13.686Z

Link: CVE-2026-4706

Vulnrichment

Updated: 2026-03-25T19:38:29.729Z

NVD

Status : Modified

Published: 2026-03-24T13:16:06.503

Modified: 2026-04-13T15:17:40.580

Link: CVE-2026-4706

Redhat

Severity : Moderate

Publid Date: 2026-03-24T12:30:33Z

Links: CVE-2026-4706 - Bugzilla

OpenCVE Enrichment

Updated: 2026-04-14T16:43:04Z

Weaknesses

Impact

Affected Systems

Risk and Exploitability

Tracking

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

Exploitation none

Automatable yes

Technical Impact partial

Subscriptions

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