Observable discrepancy in Mozilla Firefox
Priority LOW 21CWE-203Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- Partial Red Hat: 14 fixed, 1 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-203.
Summary
Navigation events were not fully adhering to the W3C's "Navigation-Timing Level 2" draft specification in some instances for the unload event, which restricts access to detailed timing attributes to only be same-origin. This resulted in potential cross-origin information exposure of history through timing side-channel attacks. This vulnerability affects Firefox < 69, Thunderbird < 68.1, Thunderbird < 60.9, Firefox ESR < 60.9, and Firefox ESR < 68.1.
Why it matters now
EPSS 0.01798 78th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial Firefox (Mozilla): 69Thunderbird (Mozilla): 68.1, 60.9+1 more productRed Hat: 6 advisoriesRed Hat: 14 fixed, 1 without a fix
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Mozilla | Firefox | before 69 | 69 | Patch available | CNA |
| Mozilla | Thunderbird | before 68.1; before 60.9 | 68.1, 60.9 | Patch available | CNA |
| Mozilla | Firefox ESR | before 60.9; before 68.1 | 60.9, 68.1 | Patch available | CNA |
- Firefox VendorMozilla Affected before 69 Fixed in 69 Patch available CNA
- Thunderbird VendorMozilla Affected before 68.1; before 60.9 Fixed in 68.1, 60.9 Patch available CNA
- Firefox ESR VendorMozilla Affected before 60.9; before 68.1 Fixed in 60.9, 68.1 Patch available CNA
CPE configurations NVD · 3
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* | before 60.9.0; before 69.0 | Vulnerable | Mozilla |
| cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:* | 68.0 to before 68.1.0 | Vulnerable | Mozilla |
| cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* | before 60.9.0; 68.0 to before 68.1.0 | Vulnerable | Mozilla |
- cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* Versions before 60.9.0; before 69.0 Vulnerable ·Mozilla
- cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:* Versions 68.0 to before 68.1.0 Vulnerable ·Mozilla
- cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* Versions before 60.9.0; 68.0 to before 68.1.0 Vulnerable ·Mozilla
Remediation
- Fix · CNA Firefox (Mozilla) Fixed in 69
- Fix · CNA Thunderbird (Mozilla) Fixed in 68.1, 60.9
- Fix · CNA Firefox ESR (Mozilla) Fixed in 60.9, 68.1
Red Hat 6 advisories
- RHSA-2019:2807 Released 2019-09-19 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux Desktop (v. 6) thunderbird-60.9.0-1.el6_10
- Red Hat Enterprise Linux Server Optional (v. 6) thunderbird-60.9.0-1.el6_10
- Red Hat Enterprise Linux Workstation (v. 6) thunderbird-60.9.0-1.el6_10
- RHSA-2019:2773 Released 2019-09-19 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux Client (v. 7) thunderbird-60.9.0-1.el7_7
- Red Hat Enterprise Linux Server Optional (v. 7) thunderbird-60.9.0-1.el7_7
- Red Hat Enterprise Linux Workstation (v. 7) thunderbird-60.9.0-1.el7_7
- RHSA-2019:2774 Released 2019-09-16 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream (v. 8) thunderbird-60.9.0-2.el8_0
Show 3 more Red Hat advisories
- RHSA-2019:2694 Released 2019-09-12 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux Desktop (v. 6) firefox-60.9.0-1.el6_10
- Red Hat Enterprise Linux Desktop Optional (v. 6) firefox-60.9.0-1.el6_10
- Red Hat Enterprise Linux HPC Node Optional (v. 6) firefox-60.9.0-1.el6_10
- Red Hat Enterprise Linux Server (v. 6) firefox-60.9.0-1.el6_10
- Red Hat Enterprise Linux Server Optional (v. 6) firefox-60.9.0-1.el6_10
- Red Hat Enterprise Linux Workstation (v. 6) firefox-60.9.0-1.el6_10
- Red Hat Enterprise Linux Workstation Optional (v. 6) firefox-60.9.0-1.el6_10
- RHSA-2019:2729 Released 2019-09-12 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux Client (v. 7) firefox-60.9.0-1.el7_7
- Red Hat Enterprise Linux Client Optional (v. 7) firefox-60.9.0-1.el7_7
- Red Hat Enterprise Linux Server (v. 7) firefox-60.9.0-1.el7_7
- Red Hat Enterprise Linux Server Optional (v. 7) firefox-60.9.0-1.el7_7
- Red Hat Enterprise Linux Workstation (v. 7) firefox-60.9.0-1.el7_7
- Red Hat Enterprise Linux Workstation Optional (v. 7) firefox-60.9.0-1.el7_7
- RHSA-2019:2663 Released 2019-09-04 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream (v. 8) firefox-68.1.0-1.el8_0
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Advisory ·
Mozilla Firefox, Firefox ESR, Thunderbird — USN-4150-1
7 records Highest priority Priority MEDIUM 3 MEDIUM, 4 LOW
Other records, highest priority first
- TI-2019-08809 Use after free in Mozilla FirefoxPriority MEDIUM 42
- TI-2019-08803 Use after free in Mozilla FirefoxPriority MEDIUM 41
- TI-2019-08797 Out-of-bounds write in Mozilla FirefoxPriority MEDIUM 41
- Advisory ·
Mozilla Firefox, Firefox ESR, Thunderbird — GLSA-201911-07
6 records Highest priority Priority MEDIUM 3 MEDIUM, 3 LOW
Other records, highest priority first
- TI-2019-08809 Use after free in Mozilla FirefoxPriority MEDIUM 42
- TI-2019-08803 Use after free in Mozilla FirefoxPriority MEDIUM 41
- TI-2019-08797 Out-of-bounds write in Mozilla FirefoxPriority MEDIUM 41
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 5 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2019:2663, RHSA-2019:2774 |
| Red Hat Enterprise Linux Client (v. 7) | Fixed | RHSA-2019:2729, RHSA-2019:2773 |
| Red Hat Enterprise Linux Client Optional (v. 7) | Fixed | RHSA-2019:2729 |
| Red Hat Enterprise Linux Desktop (v. 6) | Fixed | RHSA-2019:2694, RHSA-2019:2807 |
| Red Hat Enterprise Linux Desktop Optional (v. 6) | Fixed | RHSA-2019:2694 |
| Red Hat Enterprise Linux HPC Node Optional (v. 6) | Fixed | RHSA-2019:2694 |
| Red Hat Enterprise Linux Server (v. 6) | Fixed | RHSA-2019:2694 |
| Red Hat Enterprise Linux Server (v. 7) | Fixed | RHSA-2019:2729 |
| Red Hat Enterprise Linux Server Optional (v. 6) | Fixed | RHSA-2019:2694, RHSA-2019:2807 |
| Red Hat Enterprise Linux Server Optional (v. 7) | Fixed | RHSA-2019:2729, RHSA-2019:2773 |
| Red Hat Enterprise Linux Workstation (v. 6) | Fixed | RHSA-2019:2694, RHSA-2019:2807 |
| Red Hat Enterprise Linux Workstation (v. 7) | Fixed | RHSA-2019:2729, RHSA-2019:2773 |
| Red Hat Enterprise Linux Workstation Optional (v. 6) | Fixed | RHSA-2019:2694 |
| Red Hat Enterprise Linux Workstation Optional (v. 7) | Fixed | RHSA-2019:2729 |
Timeline
- 2026-10-02 Threatist record created from CVE-2019-11743
- 2026-10-03 Alias added: GHSA-98fg-hp5j-cm68
References
Advisory 12
- https://bugzilla.mozilla.org/show_bug.cgi?id=1560495
- https://www.mozilla.org/security/advisories/mfsa2019-25/
- https://www.mozilla.org/security/advisories/mfsa2019-27/
- https://www.mozilla.org/security/advisories/mfsa2019-26/
- https://www.mozilla.org/security/advisories/mfsa2019-29/
- https://www.mozilla.org/security/advisories/mfsa2019-30/
- openSUSE-SU-2019:2248
- openSUSE-SU-2019:2249
- openSUSE-SU-2019:2251
- openSUSE-SU-2019:2260
- USN-4150-1
- GLSA-201911-07
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-2019-11743 · CVE Program
- CVE-2019-11743 · NVD
- FIRST EPSS
- GHSA-98fg-hp5j-cm68 · GitHub Advisory Database · CC BY 4.0
- CVE-2019-11743 · Red Hat security data · CC BY 4.0
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