Recommended action

Review the upstream advisory, identify the affected product in your inventory, and apply the vendor update when one is available.

What this means

CVE-2026-5735 is listed in the HOL Guard supply-chain feed, but affected software is not mapped to a package. Review the upstream advisory for the affected product and vendor guidance. Memory safety bugs present in Firefox 149.0.1 and Thunderbird 149.0.1. 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 149.0.2 and Thunderbird 149.0.2.

Affected software

Affected software not mapped. Review the upstream record for vendor-specific product and version guidance.

Evidence and references

• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025475%2C2025477
• https://www.mozilla.org/security/advisories/mfsa2026-25/

Recommended action

Review the upstream advisory, identify the affected product in your inventory, and apply the vendor update when one is available.

What this means

CVE-2026-5735 is listed in the HOL Guard supply-chain feed, but affected software is not mapped to a package. Review the upstream advisory for the affected product and vendor guidance. Memory safety bugs present in Firefox 149.0.1 and Thunderbird 149.0.1. 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 149.0.2 and Thunderbird 149.0.2.

Affected software

Affected software not mapped. Review the upstream record for vendor-specific product and version guidance.

Evidence and references

• https://bugzilla.mozilla.org/buglist.cgi?bug_id=2025475%2C2025477
• https://www.mozilla.org/security/advisories/mfsa2026-25/