Firefox vulnerability

Use-after-free in the SVG component. This vulnerability was fixed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, Firefox ESR 153.3, Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.

Published 15 Sep 2026Updated 6 Oct 20268 sources
CVSS 8.8

What happened

Use-after-free in the SVG component. This vulnerability was fixed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, Firefox ESR 153.3, Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.

Affected versions

Firefox: before 115.41.0; 116.0 through before 140.16.0; 141.0 through before 153.3.0; 154.0.0 through before 156.0.0; before 140.16.0; 154.0 through before 156.0 Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

  • Apply vendor-provided updates or mitigations.
  • Review affected product exposure and access logs.

Public PoC references

No public PoC reference has passed the current publication threshold.