CVE-2014-1558

CVE-2014-1558 is a medium-severity vulnerability in Mozilla Firefox with a CVSS 2.0 base score of 4.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

Mozilla Firefox before 31.0 and Thunderbird before 31.0 allow remote attackers to cause a denial of service (X.509 certificate parsing outage) via a crafted certificate that does not use UTF-8 character encoding in a required context, a different vulnerability than CVE-2014-1559.

Frequently asked questions

What is CVE-2014-1558?
Mozilla Firefox before 31.0 and Thunderbird before 31.0 allow remote attackers to cause a denial of service (X.509 certificate parsing outage) via a crafted certificate that does not use UTF-8 character encoding in a required context, a different vulnerability than CVE-2014-1559.
How severe is CVE-2014-1558?
CVE-2014-1558 has a CVSS 2.0 base score of 4.3, rated medium severity.
Is CVE-2014-1558 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (64th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2014-1558?
CVE-2014-1558 primarily affects Mozilla Firefox. In total, 11 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2014-1558?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2014-1558 published?
CVE-2014-1558 was published on 2014-07-23 and last updated on 2026-06-17.

References

Affected products (11)

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