Memory safety bugs present in Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird ESR 140.9, 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, Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity High

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

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 0.00055.

Exploitation none

Automatable no

Technical Impact total

Affected Vendors & Products

Vendors Products
Mozilla Subscribe
Firefox Subscribe

Configuration 1 [-]

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

No data.

OpenCVE Enrichment is a feature of OpenCVE that uses AI to automatically link vendors and products to CVEs. Learn more on GitHub.

Vendors Products
Mozilla Subscribe
Firefox Subscribe
Advisories
Source ID Title
Debian DLA Debian DLA DLA-4546-1 firefox-esr security update
Debian DLA Debian DLA DLA-4549-1 thunderbird security update
Debian DSA Debian DSA DSA-6225-1 firefox-esr security update
Debian DSA Debian DSA DSA-6229-1 thunderbird security update
Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://access.redhat.com/errata/RHSA-2026:10757 cve-icon
https://access.redhat.com/errata/RHSA-2026:10766 cve-icon
https://access.redhat.com/errata/RHSA-2026:10767 cve-icon
https://access.redhat.com/errata/RHSA-2026:12285 cve-icon
https://access.redhat.com/errata/RHSA-2026:13537 cve-icon
https://access.redhat.com/errata/RHSA-2026:15892 cve-icon
https://access.redhat.com/errata/RHSA-2026:17477 cve-icon
https://access.redhat.com/errata/RHSA-2026:17687 cve-icon
https://access.redhat.com/errata/RHSA-2026:17688 cve-icon
https://access.redhat.com/errata/RHSA-2026:17689 cve-icon
https://access.redhat.com/errata/RHSA-2026:17690 cve-icon
https://access.redhat.com/errata/RHSA-2026:19041 cve-icon
https://access.redhat.com/errata/RHSA-2026:19131 cve-icon
https://access.redhat.com/errata/RHSA-2026:19201 cve-icon
https://access.redhat.com/errata/RHSA-2026:19348 cve-icon
https://access.redhat.com/errata/RHSA-2026:19461 cve-icon
https://access.redhat.com/errata/RHSA-2026:19462 cve-icon
https://access.redhat.com/errata/RHSA-2026:19463 cve-icon
https://access.redhat.com/errata/RHSA-2026:19464 cve-icon
https://access.redhat.com/errata/RHSA-2026:19465 cve-icon
https://access.redhat.com/errata/RHSA-2026:19466 cve-icon
https://access.redhat.com/errata/RHSA-2026:19467 cve-icon
https://access.redhat.com/errata/RHSA-2026:19468 cve-icon
https://access.redhat.com/errata/RHSA-2026:19469 cve-icon
https://access.redhat.com/errata/RHSA-2026:19542 cve-icon
https://access.redhat.com/errata/RHSA-2026:19655 cve-icon
https://access.redhat.com/errata/RHSA-2026:19704 cve-icon
https://access.redhat.com/security/cve/CVE-2026-6785 cve-icon
https://bugzilla.mozilla.org/buglist.cgi?bug_id=1935995%2C1999158%2C2015952%2C2021909%2C2022026%2C2022041%2C2022088%2C2022276%2C2022335%2C2022338%2C2022373%2C2022597%2C2022874%2C2023276%2C2023544%2C2023551%2C2023599%2C2023608%2C2023814%2C2024233%2C2024239%2C2024241%2C2024242%2C2024250%2C2024251%2C2024343%2C2024422%2C2024425%2C2024440%2C2024442%2C2024446%2C2024458%2C2024463%2C2024478%2C2024650%2C2024653%2C2024654%2C2024655%2C2024656%2C2024661%2C2024662%2C2024668%2C2024919%2C2025278%2C2025349%2C2025350%2C2025354%2C2025360%2C2025363%2C2025370%2C2025379%2C2025381%2C2025399%2C2025400%2C2025403%2C2025407%2C2025415%2C2025420%2C2025427%2C2025429%2C2025430%2C2025479%2C2025489%2C2025493%2C2025497%2C2025502%2C2025515%2C2025517%2C2025526%2C2025609%2C2025948%2C2025949%2C2025951%2C2025953%2C2025955%2C2025962%2C2025969%2C2025970%2C2025971%2C2025973%2C2025976%2C2025977%2C2026280%2C2026285%2C2026293%2C2026296%2C2026310%2C2027237%2C2027260%2C2027268%2C2027277%2C2027284%2C2027291%2C2027293%2C2027298%2C2027330%2C2027342%2C2027345%2C2027359%2C2027365%2C2027378%2C2027754%2C2027959%2C2027962%2C2027964%2C2027971%2C2027974%2C2027979%2C2027982%2C2027995%2C2028001%2C2028267%2C2028268%2C2028275%2C2028288%2C2028290%2C2028291%2C2028528%2C2028551%2C2028627%2C2028879%2C2028889%2C2029061%2C2029071%2C2029283%2C2029296%2C2029314%2C2029323%2C2029411%2C2029423%2C2029424%2C2029425%2C2029427%2C2029436%2C2029440%2C2029449%2C2029450%2C2029458%2C2029462%2C2029468%2C2029472%2C2029690%2C2029707%2C2029708%2C2029728%2C2029802%2C2029896%2C2029906%2C2030106%2C2030118%2C2030123%2C2030135%2C2030230%2C2030320 cve-icon cve-icon
https://bugzilla.redhat.com/show_bug.cgi?id=2460104 cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2026-6785 cve-icon
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6785.json cve-icon
https://www.cve.org/CVERecord?id=CVE-2026-6785 cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-30/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-31/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-31/#CVE-2026-6785 cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-32/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-32/#CVE-2026-6785 cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-33/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-34/ cve-icon cve-icon
History

Wed, 27 May 2026 18:30:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H'}

 cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H'}

Tue, 28 Apr 2026 20:00:00 +0000

Type Values Removed Values Added
First Time appeared Mozilla thunderbird
CPEs cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*
Vendors & Products Mozilla thunderbird

Wed, 22 Apr 2026 12:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

 threat_severity

Important

Wed, 22 Apr 2026 00:00:00 +0000

Type Values Removed Values Added
Description Memory safety bugs present in Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird ESR 140.9, 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, Firefox ESR 115.35, and Firefox ESR 140.10. Memory safety bugs present in Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird ESR 140.9, 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, Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
References

Tue, 21 Apr 2026 17:30:00 +0000

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

Tue, 21 Apr 2026 14:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-125
CWE-416
CWE-787
Metrics cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Tue, 21 Apr 2026 13:15:00 +0000

Type Values Removed Values Added
Description Memory safety bugs present in Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird ESR 140.9, 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, Firefox ESR 115.35, and Firefox ESR 140.10.
Title Memory safety bugs fixed in Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird ESR 140.10, Firefox 150 and Thunderbird 150
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: mozilla

Published:

Updated: 2026-07-15T00:40:41.733Z

Reserved: 2026-04-21T12:41:13.671Z

Link: CVE-2026-6785

cve-icon Vulnrichment

Updated: 2026-07-15T00:40:41.733Z

cve-icon NVD

Status : Modified

Published: 2026-04-26T19:53:39.010

Modified: 2026-07-15T01:16:55.450

Link: CVE-2026-6785

cve-icon Redhat

Severity : Important

Publid Date: 2026-04-21T12:41:13Z

Links: CVE-2026-6785 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-05-27T22:30:35Z

Weaknesses