Internally found bugs fixed in Firefox ESR 140.14, Firefox ESR 153.1 and Firefox 154

Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

Severity and exploitation

• CISA KEV Not listed.
• EPSS 0.0052, the 44th percentile, on 9 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

This record came from the full history of the CVE Program, published 18 Aug 2026. New records show when each source confirmed them.

Sources

• CVE List: CVE-2026-74987
• NVD: CVE-2026-74987

References from the CNA

• bugzilla.mozilla.org/buglist.cgi?bug_id=1500946%2C1788109%2C2045379%2C2045380%2C2049339%2C2049393%2C2053580%2C2054662%2C2054665%2C2054673%2C2054785%2C2058645
• bugzilla.mozilla.org/buglist.cgi?bug_id=2048797%2C2050536%2C2053272%2C2053579%2C2057115%2C2057116%2C2057130%2C2057991%2C2057995%2C2058002%2C2058008%2C2058032%2C2058102%2C2058667
• bugzilla.mozilla.org/show_bug.cgi?id=2059424
• www.mozilla.org/security/advisories/mfsa2026-74/
• www.mozilla.org/security/advisories/mfsa2026-76/
• www.mozilla.org/security/advisories/mfsa2026-77/
• www.mozilla.org/security/advisories/mfsa2026-78/
• www.mozilla.org/security/advisories/mfsa2026-79/
• www.mozilla.org/security/advisories/mfsa2026-80/

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.