Information disclosure in Mozilla Firefox
Priority MEDIUM 41CWE-200Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- Low · None · Low
- 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-200.
Summary
Other issue in the Storage: IndexedDB 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 0.03883 90th 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
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Mozilla | Firefox | — | 140.10, 150 | Patch available | CNA |
| Mozilla | Thunderbird | — | 140.10, 150 | Patch available | CNA |
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 Importantfirefox 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 Importantfirefox 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 Importantfirefox 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 Importantthunderbird 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 Importantfirefox 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 Importantthunderbird 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 Importantthunderbird 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 Importantthunderbird 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 Importantthunderbird 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 Importantthunderbird 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 Importantthunderbird 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 Importantthunderbird 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 Importantthunderbird 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 Importantfirefox 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 Importantthunderbird 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 Importantfirefox 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 Importantfirefox 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 Importantfirefox 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 Importantfirefox 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 Importantfirefox 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 Importantfirefox 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 Importantthunderbird 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 Importantthunderbird 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 Importantthunderbird 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 Importantfirefox 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 Importantfirefox 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 Importantfirefox 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 →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No 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
- 2026-10-02 Threatist record created from CVE-2026-6770
- 2026-10-03 Alias added: GHSA-rx3r-9q8p-8rrj
- 2026-10-25 EPSS moved to the 90th–95th percentile
- 2026-10-25 Priority changed: LOW → MEDIUM
References
More Mozilla Firefox vulnerabilities
- 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
Sources
- CVE-2026-6770 · CVE Program
- CVE-2026-6770 · NVD
- FIRST EPSS
- GHSA-rx3r-9q8p-8rrj · GitHub Advisory Database · CC BY 4.0
- CVE-2026-6770 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences