Widely-used Firefox/Thunderbird; potential remote code execution via JIT WebAssembly miscompilation, high risk across user environments.
CVE-2026-2796
Critical JIT WebAssembly miscompilation in Firefox/Thunderbird.
Is CVE-2026-2796 being exploited?
Not confirmed. CVE-2026-2796 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.65% probability of exploitation in the next 30 days.
How severe is CVE-2026-2796?
CVE-2026-2796 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-2796?
Yes. A fix has been recorded for CVE-2026-2796. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-2796 affect?
CVE-2026-2796 affects Firefox < 148, Thunderbird < 148. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-2796?
Patch when released; enable auto-updates; monitor for exploits.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote code execution via crafted WebAssembly in Firefox/Thunderbird; attacker could run code with user privileges.
Patch when possible