CVE-2017-5386

CVE-2017-5386 is a high-severity vulnerability in Mozilla Firefox with a CVSS 3.x base score of 7.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

WebExtension scripts can use the "data:" protocol to affect pages loaded by other web extensions using this protocol, leading to potential data disclosure or privilege escalation in affected extensions. This vulnerability affects Firefox ESR < 45.7 and Firefox < 51.

Frequently asked questions

What is CVE-2017-5386?
WebExtension scripts can use the "data:" protocol to affect pages loaded by other web extensions using this protocol, leading to potential data disclosure or privilege escalation in affected extensions. This vulnerability affects Firefox ESR < 45.7 and Firefox < 51.
How severe is CVE-2017-5386?
CVE-2017-5386 has a CVSS 3.x base score of 7.3, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2017-5386 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-5386?
CVE-2017-5386 primarily affects Mozilla Firefox. In total, 19 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2017-5386?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2017-5386 published?
CVE-2017-5386 was published on 2018-06-11 and last updated on 2026-06-17.

References

Affected products (19)

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