What’s Vulnerable › Vulnerabilities

CVE-2019-9805

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2019-04-26 · updated 2026-06-17
• Weakness: CWE-908

Description

A latent vulnerability exists in the Prio library where data may be read from uninitialized memory for some functions, leading to potential memory corruption. This vulnerability affects Firefox < 66.

Affected products

• Mozilla Firefox: before 66.0 — fixed in 66.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 66.0. Check the vendor advisory for mitigations.

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=1521360
• https://www.mozilla.org/security/advisories/mfsa2019-07/
• https://bugzilla.mozilla.org/show_bug.cgi?id=1521360
• https://www.mozilla.org/security/advisories/mfsa2019-07/

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