What’s Vulnerable › Vulnerabilities

CVE-2017-5396

• Severity: critical (CVSS 9.8 v3.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 4.0% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2018-06-11 · updated 2026-06-17
• Weakness: CWE-416

Description

A use-after-free vulnerability in the Media Decoder when working with media files when some events are fired after the media elements are freed from memory. This vulnerability affects Thunderbird < 45.7, Firefox ESR < 45.7, and Firefox < 51.

Affected products

• Debian Linux: 8.0
• Mozilla Firefox: before 51.0; before 45.7.0 — fixed in 45.7.0, 51.0
• Mozilla Thunderbird: before 45.7.0 — fixed in 45.7.0
• Red Hat Enterprise Linux: 5.0, 6.0, 7.0
• RedHat Enterprise Linux Desktop: 5.0, 6.0, 7.0
• RedHat Enterprise Linux Server: 5.0, 6.0, 7.0
• RedHat Enterprise Linux Server Aus: 7.3, 7.4
• RedHat Enterprise Linux Server Eus: 7.3, 7.4, 7.5
• RedHat Enterprise Linux Workstation: 5.0, 6.0, 7.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 45.7.0, 51.0; Mozilla Thunderbird 45.7.0. Check the vendor advisory for mitigations.

References

• http://rhn.redhat.com/errata/RHSA-2017-0190.html
• http://rhn.redhat.com/errata/RHSA-2017-0238.html
• http://www.securityfocus.com/bid/95769
• http://www.securitytracker.com/id/1037693
• https://bugzilla.mozilla.org/show_bug.cgi?id=1329403
• https://security.gentoo.org/glsa/201702-13
• https://security.gentoo.org/glsa/201702-22
• https://www.debian.org/security/2017/dsa-3771
• https://www.debian.org/security/2017/dsa-3832
• https://www.mozilla.org/security/advisories/mfsa2017-01/
• https://www.mozilla.org/security/advisories/mfsa2017-02/
• https://www.mozilla.org/security/advisories/mfsa2017-03/

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