What’s Vulnerable › Vulnerabilities

CVE-2019-11743

• Severity: low (CVSS 3.7 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.8% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2019-09-27 · updated 2026-06-17
• Weakness: CWE-203

Description

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.

Affected products

• Mozilla Firefox: before 60.9.0; before 69.0 — fixed in 60.9.0, 69.0
• Mozilla Firefox ESR: from 68.0 before 68.1.0 — fixed in 68.1.0
• Mozilla Thunderbird: before 60.9.0; from 68.0 before 68.1.0 — fixed in 60.9.0, 68.1.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 60.9.0, 69.0; Mozilla Firefox ESR 68.1.0; Mozilla Thunderbird 60.9.0, 68.1.0. Check the vendor advisory for mitigations.

References

• http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00009.html
• http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00010.html
• http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00011.html
• http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00017.html
• https://bugzilla.mozilla.org/show_bug.cgi?id=1560495
• https://security.gentoo.org/glsa/201911-07
• https://usn.ubuntu.com/4150-1/
• https://w3c.github.io/navigation-timing
• https://www.mozilla.org/security/advisories/mfsa2019-25/
• https://www.mozilla.org/security/advisories/mfsa2019-26/
• https://www.mozilla.org/security/advisories/mfsa2019-27/
• https://www.mozilla.org/security/advisories/mfsa2019-29/

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