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CRITICAL

CVE-2017-5434

CVSS v3

9.8

CRITICAL

EPSS Score

3.5 %

exploit probability, as of 2026-10-19

CISA KEV

No

known exploited

Exploitation

—

SSVC status

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Affected and fixed versions

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

  • CVE-2017-5434 Red Hat Product Security241 products fixed · 2 known affected

    Mozilla: Use-after-free during focus handling (MFSA 2017-11, MFSA 2017-12)

    firefox as a component of Red Hat Enterprise Linux 5 · thunderbird as a component of Red Hat Enterprise Linux 5

  • RHSA-2017:1201 Red Hat Product Security32 products fixed

    Red Hat Security Advisory: thunderbird security update

  • RHSA-2017:1106 Red Hat Product Security27 products fixed

    Red Hat Security Advisory: firefox security update

  • RHSA-2017:1104 Red Hat Product Security34 products fixed

    Red Hat Security Advisory: firefox security update

Full record on NVD

Description

A use-after-free vulnerability occurs when redirecting focus handling which results in a potentially exploitable crash. This vulnerability affects Thunderbird < 52.1, Firefox ESR < 45.9, Firefox ESR < 52.1, and Firefox < 53.

Technical details

Published
2018-06-11

Frequently asked questions

What is CVE-2017-5434?

A use-after-free vulnerability occurs when redirecting focus handling which results in a potentially exploitable crash. This vulnerability affects Thunderbird < 52.1, Firefox ESR < 45.9, Firefox ESR < 52.1, and Firefox < 53.

Is CVE-2017-5434 actively exploited?

Active exploitation of CVE-2017-5434 has not been confirmed. Its EPSS score was 3.5% on 2026-10-19, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2017-5434?

CVE-2017-5434 has a CVSS v3 base score of 9.8 (CRITICAL severity).

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