What’s Vulnerable › Vulnerabilities

CVE-2017-5403

• Severity: critical (CVSS 9.8 v3.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2018-06-11 · updated 2026-06-17
• Weakness: CWE-416

Description

When adding a range to an object in the DOM, it is possible to use "addRange" to add the range to an incorrect root object. This triggers a use-after-free, resulting in a potentially exploitable crash. This vulnerability affects Firefox < 52 and Thunderbird < 52.

Affected products

• Mozilla Firefox: before 52.0 — fixed in 52.0
• Mozilla Thunderbird: before 52.0 — fixed in 52.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 52.0; Mozilla Thunderbird 52.0. Check the vendor advisory for mitigations.

References

• http://www.securityfocus.com/bid/96691
• http://www.securitytracker.com/id/1037966
• https://bugzilla.mozilla.org/show_bug.cgi?id=1340186
• https://www.mozilla.org/security/advisories/mfsa2017-05/
• https://www.mozilla.org/security/advisories/mfsa2017-09/
• http://www.securityfocus.com/bid/96691
• http://www.securitytracker.com/id/1037966
• https://bugzilla.mozilla.org/show_bug.cgi?id=1340186
• https://www.mozilla.org/security/advisories/mfsa2017-05/
• https://www.mozilla.org/security/advisories/mfsa2017-09/

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