CVE-2026-74950CWE-269privilege-escalation

CVE-2026-74950

High · published August 18, 2026

CVSS v3.1

8.8

EPSS

Percentile

34.7

In the wild

Unconfirmed

What it is

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

The record

Technical detail

CVSS v3.1: 8.8 · HIGH
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS v4.0: Not supplied
EPSS: 0.00415 · 34.7th percentile
Weakness: CWE-269 · Improper Privilege Management
Published: 2026-08-18T17:17Z

Affected products (4)

Product	Versions	Fixed in
mozilla/firefox	< 153.1.0	153.1.0
mozilla/firefox	< 154.0.0	154.0.0
mozilla/thunderbird	< 153.1.0	153.1.0
mozilla/thunderbird	< 154.0	154.0

References (5)

https://bugzilla.mozilla.org/show_bug.cgi?id=1880253 · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-74/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-77/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-78/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-80/ · [email protected]

EPSS history

Timeline

18 AUG 12:23Z
Privilege escalation in the Downloads API component
cvelistv5