CVE-2026-6785
Memory safety bugs fixed in Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird ESR 140.10, Firefox 150 and Thunderbird 150
CVSS Score
7.5
EPSS Score
0.0%
EPSS Percentile
0th
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.
| Vendor | mozilla |
| Product | firefox |
| Ecosystems | |
| Industries | Technology |
| Published | Apr 21, 2026 |
| Last Updated | Jul 15, 2026 |
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Affected Versions
Mozilla / Firefox
All versions affected Mozilla / Thunderbird
All versions affected References
bugzilla.mozilla.org: 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 mozilla.org: https://www.mozilla.org/security/advisories/mfsa2026-30/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2026-31/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2026-32/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2026-33/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2026-34/ access.redhat.com: https://access.redhat.com/security/cve/CVE-2026-6785 bugzilla.redhat.com: https://bugzilla.redhat.com/show_bug.cgi?id=2460104 security.access.redhat.com: https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6785.json access.redhat.com: https://access.redhat.com/errata/RHSA-2026:19704 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:17690 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:19463 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:10767 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:12285 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:19041 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:19131 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:10766 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:13537 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:19655 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:19465 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:19542 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:19466 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:17477 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:19467 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:17687 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:19468 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:17689 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:19461 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:19464 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:19469 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:17688 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:19462 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:10757 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:15892 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:19201 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:19348
Credits
Andrew McCreight, Ashley Zebrowski, Brian Grinstead, Christian Holler, Maurice Dauer, Tom Schuster and the Mozilla Fuzzing Team