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BoardVulnerabilities › CVE-2026-84142
9.8Critical CVE-2026-84142 Mozilla

Internally found bugs present in Thunderbird 154.

Internally found bugs present in Thunderbird 154. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 155 and Thunderbird 155.

What happened

Internally found bugs present in Thunderbird 154. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 155 and Thunderbird 155.

Does it affect you

Not enough information

No products recorded, so this cannot be matched against anything.

What to do

  • Follow the vendor advisory for the fixed release and any interim mitigation.
    mozilla.org
  • Follow the vendor advisory for the fixed release and any interim mitigation.
    mozilla.org

Vendor's affected list

firefox
Everything below 155.0.0

Sources

A verdict here is derived from what you told us and what the vendor published. It is not an assessment of your environment. Why we never say you are safe.