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Vulnerability record · CVE-2026-74950 · published 18 August 2026

CVE-2026-74950: Mozilla firefox improper privilege management vulnerability

Mozilla · Firefox

Privilege escalation in the Downloads API component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.

8.8 CVSS 3.1 High EPSS 0.42% · top 66.7% CWE-269 · Improper privilege management
8.8CVSS 3.1 base score
0.42%EPSS exploitation probability, 30 days
NoNot in CISA KEV
2Affected product versions listed by NVD
5References
21 Aug 2026Last modified by NVD

Description

Privilege escalation in the Downloads API component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected products

2 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://bugzilla.mozilla.org/show_bug.cgi?id=1880253 Permissions Required
https://www.mozilla.org/security/advisories/mfsa2026-74/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-77/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-78/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-80/ Vendor Advisory

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Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2026-74950), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.