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TI-2026-05926 Aliases CVE-2026-6761GHSA-5mff-cxq5-82jv

Improper privilege management in Mozilla Firefox

Priority LOW 39CWE-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: 16 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 Networking component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00221 12th percentileScored 2026-11-07
Fix Partial Firefox (Mozilla): 140.10, 150Thunderbird (Mozilla): 140.10, 150Red Hat: 27 advisoriesRed Hat: 16 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—140.10, 150Patch availableCNA
MozillaThunderbird—140.10, 150Patch availableCNA
  • Firefox VendorMozilla Affected — Fixed in 140.10, 150 Patch available CNA
  • Thunderbird VendorMozilla Affected — Fixed in 140.10, 150 Patch available CNA

CPE configurations NVD · 3

CPEVersionsRoleVendor
cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*before 140.10.0VulnerableMozilla
cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*before 150.0VulnerableMozilla
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*before 140.10.0VulnerableMozilla
  • cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* Versions before 140.10.0 Vulnerable ·Mozilla
  • cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:* Versions before 150.0 Vulnerable ·Mozilla
  • cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:* Versions before 140.10.0 Vulnerable ·Mozilla

Remediation

  • Fix · CNA Firefox (Mozilla) Fixed in 140.10, 150
  • Fix · CNA Thunderbird (Mozilla) Fixed in 140.10, 150

Red Hat 27 advisories

  • RHSA-2026:19704 Released 2026-05-20 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux Server (v. 7 ELS) firefox-140.10.0-2.el7_9
  • RHSA-2026:19655 Released 2026-05-20 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.4) firefox-140.10.0-1.el8_4
    • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) firefox-140.10.0-1.el8_4
  • RHSA-2026:19542 Released 2026-05-20 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.6) firefox-140.10.0-1.el8_6
    • Red Hat Enterprise Linux AppStream E4S (v.8.6) firefox-140.10.0-1.el8_6
    • Red Hat Enterprise Linux AppStream TUS (v.8.6) firefox-140.10.0-1.el8_6
Show 24 more Red Hat advisories
  • RHSA-2026:19462 Released 2026-05-20 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) thunderbird-140.10.0-1.el9_6
  • RHSA-2026:19464 Released 2026-05-20 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.4) firefox-140.10.0-1.el9_4, firefox-x11-140.10.0-1.el9_4
  • RHSA-2026:19466 Released 2026-05-20 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.6) thunderbird-140.10.0-1.el8_6
    • Red Hat Enterprise Linux AppStream E4S (v.8.6) thunderbird-140.10.0-1.el8_6
    • Red Hat Enterprise Linux AppStream TUS (v.8.6) thunderbird-140.10.0-1.el8_6
  • RHSA-2026:19469 Released 2026-05-20 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.4) thunderbird-140.10.0-1.el9_4
  • RHSA-2026:19467 Released 2026-05-20 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream E4S (v.8.8) thunderbird-140.10.0-1.el8_8
    • Red Hat Enterprise Linux AppStream TUS (v.8.8) thunderbird-140.10.0-1.el8_8
  • RHSA-2026:19468 Released 2026-05-20 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.0) thunderbird-140.10.0-1.el9_0
  • RHSA-2026:19463 Released 2026-05-20 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream EUS (v. 10.0) thunderbird-140.10.0-1.el10_0
  • RHSA-2026:19465 Released 2026-05-20 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.4) thunderbird-140.10.0-1.el8_4
    • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) thunderbird-140.10.0-1.el8_4
  • RHSA-2026:19461 Released 2026-05-20 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.2) thunderbird-140.10.0-1.el9_2
  • RHSA-2026:19348 Released 2026-05-19 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream (v. 9) thunderbird-140.10.1-1.el9_8
  • RHSA-2026:19201 Released 2026-05-19 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream (v. 9) firefox-140.10.0-1.el9_8, firefox-x11-140.10.0-1.el9_8
  • RHSA-2026:19131 Released 2026-05-19 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream (v. 10) thunderbird-140.10.0-1.el10_2
  • RHSA-2026:19041 Released 2026-05-19 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream (v. 10) firefox-140.10.0-1.el10_2
  • RHSA-2026:17688 Released 2026-05-14 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) firefox-140.10.0-1.el9_6, firefox-x11-140.10.0-1.el9_6
  • RHSA-2026:17689 Released 2026-05-14 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.2) firefox-140.10.0-1.el9_2, firefox-x11-140.10.0-1.el9_2
  • RHSA-2026:17687 Released 2026-05-14 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.0) firefox-140.10.0-1.el9_0
  • RHSA-2026:17690 Released 2026-05-14 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream EUS (v. 10.0) firefox-140.10.0-1.el10_0
  • RHSA-2026:17477 Released 2026-05-14 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream E4S (v.8.8) firefox-140.10.0-1.el8_8
    • Red Hat Enterprise Linux AppStream TUS (v.8.8) firefox-140.10.0-1.el8_8
  • RHSA-2026:15892 Released 2026-05-11 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream (v. 9) thunderbird-140.10.0-1.el9_7
  • RHSA-2026:13537 Released 2026-05-04 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream (v. 8) thunderbird-140.10.0-1.el8_10
  • RHSA-2026:12285 Released 2026-04-30 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream (v. 10) thunderbird-140.10.0-1.el10_1
  • RHSA-2026:10766 Released 2026-04-27 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream (v. 8) firefox-140.10.0-1.el8_10
  • RHSA-2026:10767 Released 2026-04-27 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream (v. 10) firefox-140.10.0-1.el10_1
  • RHSA-2026:10757 Released 2026-04-27 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream (v. 9) firefox-140.10.0-1.el9_7, firefox-x11-140.10.0-1.el9_7

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-2026:10767, RHSA-2026:12285, RHSA-2026:19041, RHSA-2026:19131
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2026:10766, RHSA-2026:13537
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:10757, RHSA-2026:15892, RHSA-2026:19201, RHSA-2026:19348
Red Hat Enterprise Linux AppStream AUS (v.8.4)Fixed RHSA-2026:19465, RHSA-2026:19655
Red Hat Enterprise Linux AppStream AUS (v.8.6)Fixed RHSA-2026:19466, RHSA-2026:19542
Red Hat Enterprise Linux AppStream E4S (v.8.6)Fixed RHSA-2026:19466, RHSA-2026:19542
Red Hat Enterprise Linux AppStream E4S (v.8.8)Fixed RHSA-2026:17477, RHSA-2026:19467
Red Hat Enterprise Linux AppStream E4S (v.9.0)Fixed RHSA-2026:17687, RHSA-2026:19468
Red Hat Enterprise Linux AppStream E4S (v.9.2)Fixed RHSA-2026:17689, RHSA-2026:19461
Red Hat Enterprise Linux AppStream EUS (v. 10.0)Fixed RHSA-2026:17690, RHSA-2026:19463
Red Hat Enterprise Linux AppStream EUS (v.9.4)Fixed RHSA-2026:19464, RHSA-2026:19469
Red Hat Enterprise Linux AppStream EUS (v.9.6)Fixed RHSA-2026:17688, RHSA-2026:19462
Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)Fixed RHSA-2026:19465, RHSA-2026:19655
Red Hat Enterprise Linux AppStream TUS (v.8.6)Fixed RHSA-2026:19466, RHSA-2026:19542
Red Hat Enterprise Linux AppStream TUS (v.8.8)Fixed RHSA-2026:17477, RHSA-2026:19467
Red Hat Enterprise Linux Server (v. 7 ELS)Fixed RHSA-2026:19704

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-6761
  2. 2026-10-03 Alias added: GHSA-5mff-cxq5-82jv
  3. 2026-10-25 Priority changed: MEDIUM → LOW

References

Advisory 4

Other 1

  • 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