CVE-2026-6784

Memory safety bugs fixed in Firefox 150 and Thunderbird 150

CVSS 7.5 HIGHEPSS 0.3%CWE-125 CWE-416 CWE-787

Vexday Risk Score

21Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 7.5EPSS 0.3%KEV nãoPoC —Nuclei —Metasploit —Patch —

Lifecycle

21 Apr 2026Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

Memory safety bugs present in 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 and Thunderbird 150.

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected products

Mozilla · Firefox Mozilla · Thunderbird

References

https://access.redhat.com/security/cve/CVE-2026-6784 https://bugzilla.mozilla.org/buglist.cgi?bug_id=1536243%2C1745382%2C1851073%2C1893400%2C1963301%2C2001319%2C2002899%2C2012436%2C2014435%2C2016901%2C2019916%2C2020486%2C2020612%2C2020817%2C2021788%2C2022051%2C2022367%2C2022431%2C2023302%2C2023670%2C2024225%2C2024238%2C2024240%2C2024265%2C2024367%2C2024369%2C2024424%2C2024760%2C2025281%2C2025361%2C2025387%2C2025466%2C2025954%2C2025958%2C2026278%2C2026292%2C2026297%2C2026378%2C2027148%2C2027287%2C2027341%2C2027384%2C2027427%2C2027694%2C2027993%2C2028009%2C2028270%2C2028416%2C2028524%2C2029295%2C2029699%2C2029800%2C2029801 https://bugzilla.redhat.com/show_bug.cgi?id=2460084 https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6784.json https://www.mozilla.org/security/advisories/mfsa2026-30/https://www.mozilla.org/security/advisories/mfsa2026-33/