CVE-2017-7753

CVE-2017-7753 is a critical-severity vulnerability in Mozilla Firefox with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-125.

Key facts

Description

An out-of-bounds read occurs when applying style rules to pseudo-elements, such as ::first-line, using cached style data. This vulnerability affects Thunderbird < 52.3, Firefox ESR < 52.3, and Firefox < 55.

Frequently asked questions

What is CVE-2017-7753?
An out-of-bounds read occurs when applying style rules to pseudo-elements, such as ::first-line, using cached style data. This vulnerability affects Thunderbird < 52.3, Firefox ESR < 52.3, and Firefox < 55.
How severe is CVE-2017-7753?
CVE-2017-7753 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.
Is CVE-2017-7753 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (87th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-7753?
CVE-2017-7753 primarily affects Mozilla Firefox. In total, 17 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2017-7753?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2017-7753 published?
CVE-2017-7753 was published on 2018-06-11 and last updated on 2026-06-17.

References

Affected products (17)

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