9.1
Critical
CVE-2026-74986 Site isolation issue in the CSS Parsing and Computation component
Description
Site isolation issue in the CSS Parsing and Computation component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Firefox 154 | earliest → < 154 | 154 |
| Firefox 153.1 | earliest → < 153.1 | 153.1 |
| Thunderbird 154 | earliest → < 154 | 154 |
| Thunderbird 153.1 | earliest → < 153.1 | 153.1 |
References
- bugzilla.mozilla.org bugzilla.mozilla.org
- www.mozilla.org www.mozilla.org
- www.mozilla.org www.mozilla.org
- www.mozilla.org www.mozilla.org
- www.mozilla.org www.mozilla.org
Timeline
- Published
- Last modified
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