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TI-2026-13678 Aliases CVE-2026-16371GHSA-8rfc-phx9-6vc2

Improper privilege management in Mozilla Firefox

Priority MEDIUM 40CWE-269Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Privilege escalation
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 14 fixed, 3 without a fix

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-269.

Summary

Privilege escalation in the DOM: Navigation component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, Thunderbird 140.13, Firefox ESR 140.15, and Thunderbird 140.15.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00297 22nd percentileScored 2026-11-07
Fix Partial Firefox (Mozilla): 140.13, 140.15, 153Thunderbird (Mozilla): 140.13, 140.15, 153Red Hat: 21 advisoriesRed Hat: 14 fixed, 3 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
MozillaFirefox—140.13, 140.15, 153Patch availableCNA
MozillaThunderbird—140.13, 140.15, 153Patch availableCNA
  • Firefox VendorMozilla Affected — Fixed in 140.13, 140.15, 153 Patch available CNA
  • Thunderbird VendorMozilla Affected — Fixed in 140.13, 140.15, 153 Patch available CNA

CPE configurations NVD · 3

CPEVersionsRoleVendor
cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*before 140.13.0VulnerableMozilla
cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*before 153.0.0VulnerableMozilla
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*before 140.13.0; 141.0 to before 153.0VulnerableMozilla
  • cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* Versions before 140.13.0 Vulnerable ·Mozilla
  • cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:* Versions before 153.0.0 Vulnerable ·Mozilla
  • cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* Versions before 140.13.0; 141.0 to before 153.0 Vulnerable ·Mozilla

Remediation

  • Fix · CNA Firefox (Mozilla) Fixed in 140.13, 140.15, 153
  • Fix · CNA Thunderbird (Mozilla) Fixed in 140.13, 140.15, 153

Red Hat 21 advisories

  • RHSA-2026:54339 Released 2026-08-12 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream E4S (v.8.8) firefox-140.13.0-1.el8_8
    • Red Hat Enterprise Linux AppStream TUS (v.8.8) firefox-140.13.0-1.el8_8
  • RHSA-2026:54248 Released 2026-08-12 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux Server (v. 7 ELS) firefox-140.13.0-1.el7_9
  • RHSA-2026:54249 Released 2026-08-12 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) firefox-140.13.0-1.el9_6, firefox-x11-140.13.0-1.el9_6
Show 18 more Red Hat advisories
  • RHSA-2026:54259 Released 2026-08-12 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.6) firefox-140.13.0-1.el8_6
    • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) firefox-140.13.0-1.el8_6
  • RHSA-2026:54182 Released 2026-08-12 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.4) firefox-140.13.0-1.el9_4, firefox-x11-140.13.0-1.el9_4
  • RHSA-2026:54181 Released 2026-08-12 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream EUS (v. 10.0) firefox-140.13.0-1.el10_0
  • RHSA-2026:54185 Released 2026-08-12 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.2) firefox-140.13.0-1.el9_2, firefox-x11-140.13.0-1.el9_2
  • RHSA-2026:54180 Released 2026-08-12 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.4) firefox-140.13.0-1.el8_4
    • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) firefox-140.13.0-1.el8_4
  • RHSA-2026:53475 Released 2026-08-11 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.2) thunderbird-140.13.0-1.el9_2
  • RHSA-2026:53454 Released 2026-08-11 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream E4S (v.8.8) thunderbird-140.13.0-1.el8_8
    • Red Hat Enterprise Linux AppStream TUS (v.8.8) thunderbird-140.13.0-1.el8_8
  • RHSA-2026:53453 Released 2026-08-11 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.6) thunderbird-140.13.0-1.el8_6
    • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) thunderbird-140.13.0-1.el8_6
  • RHSA-2026:53455 Released 2026-08-11 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.4) thunderbird-140.13.0-1.el8_4
    • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) thunderbird-140.13.0-1.el8_4
  • RHSA-2026:53446 Released 2026-08-11 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) thunderbird-140.13.0-1.el9_6
  • RHSA-2026:53444 Released 2026-08-11 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.4) thunderbird-140.13.0-1.el9_4
  • RHSA-2026:53445 Released 2026-08-11 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream EUS (v. 10.0) thunderbird-140.13.0-1.el10_0
  • RHSA-2026:49921 Released 2026-08-04 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream (v. 9) thunderbird-140.13.0-1.el9_8
  • RHSA-2026:49922 Released 2026-08-04 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream (v. 8) thunderbird-140.13.0-1.el8_10
  • RHSA-2026:49621 Released 2026-08-03 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream (v. 10) thunderbird-140.13.0-1.el10_2
  • RHSA-2026:47104 Released 2026-08-03 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream (v. 9) firefox-140.13.0-1.el9_8, firefox-x11-140.13.0-1.el9_8
  • RHSA-2026:47105 Released 2026-07-28 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream (v. 8) firefox-140.13.0-1.el8_10
  • RHSA-2026:47101 Released 2026-07-28 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream (v. 10) firefox-140.13.0-1.el10_2

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix yet
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 7AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:47101, RHSA-2026:49621
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2026:47105, RHSA-2026:49922
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:47104, RHSA-2026:49921
Red Hat Enterprise Linux AppStream AUS (v.8.4)Fixed RHSA-2026:53455, RHSA-2026:54180
Red Hat Enterprise Linux AppStream AUS (v.8.6)Fixed RHSA-2026:53453, RHSA-2026:54259
Red Hat Enterprise Linux AppStream E4S (v.8.8)Fixed RHSA-2026:53454, RHSA-2026:54339
Red Hat Enterprise Linux AppStream E4S (v.9.2)Fixed RHSA-2026:53475, RHSA-2026:54185
Red Hat Enterprise Linux AppStream E4S (v.9.4)Fixed RHSA-2026:53444, RHSA-2026:54182
Red Hat Enterprise Linux AppStream EUS (v. 10.0)Fixed RHSA-2026:53445, RHSA-2026:54181
Red Hat Enterprise Linux AppStream EUS (v.9.6)Fixed RHSA-2026:53446, RHSA-2026:54249
Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)Fixed RHSA-2026:53455, RHSA-2026:54180
Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6)Fixed RHSA-2026:53453, RHSA-2026:54259
Red Hat Enterprise Linux AppStream TUS (v.8.8)Fixed RHSA-2026:53454, RHSA-2026:54339
Red Hat Enterprise Linux Server (v. 7 ELS)Fixed RHSA-2026:54248

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-16371
  2. 2026-10-03 Alias added: GHSA-8rfc-phx9-6vc2

References

Advisory 4

Other 3

  • TI-2024-08981 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.8
  • TI-2022-09832 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.6
  • TI-2019-08769 Improper input validation in Mozilla Firefox ESR KEVCVSS 3.1CRITICAL 10.0
  • TI-2010-03577 Mozilla Firefox 3.5.x through 3.5.14 and 3.6.x through 3.6.11, Thunderbird 3.1.6 before… KEVCVSS 3.1CRITICAL 9.8
  • TI-2023-04799 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
  • TI-2023-04477 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
See all 3444 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences