CVE-2026-74990 is a vulnerability in Mozilla Firefox
Published on August 18, 2026
Internally found bugs fixed in Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1 and Firefox 154
Internally found bugs present in Firefox ESR 115.38, Firefox ESR 140.13, Firefox ESR 153.0 and Firefox 153. 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 154, Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1.
Products Associated with CVE-2026-74990
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Affected Versions
Mozilla Firefox:- Version 115.39, <= 115.* is unaffected.
- Version 140.14, <= 140.* is unaffected.
- Version 153.1, <= 153.* is unaffected.
- Version 154, <= * is unaffected.