How severe is CVE-2017-7838?

CVE-2017-7838 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2017-7838 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (71st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2017-7838?

CVE-2017-7838 affects Mozilla Firefox. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2017-7838?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2017-7838 published?

CVE-2017-7838 was published on 2018-06-11 and last updated on 2026-06-17.

CVE-2017-7838

CVE-2017-7838 is a medium-severity vulnerability in Mozilla Firefox with a CVSS 3.x base score of 5.3. 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-20.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 5.0
EPSS exploit prediction: 1% (71st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Mozilla Firefox
Published: 2018-06-11
Last modified: 2026-06-17

Description

Punycode format text will be displayed for entire qualified international domain names in some instances when a sub-domain triggers the punycode display instead of the primary domain being displayed in native script and the sub-domain only displaying as punycode. This could be used for limited spoofing attacks due to user confusion. This vulnerability affects Firefox < 57.

Frequently asked questions

What is CVE-2017-7838?: Punycode format text will be displayed for entire qualified international domain names in some instances when a sub-domain triggers the punycode display instead of the primary domain being displayed in native script and the sub-domain only displaying as punycode. This could be used for limited spoofing attacks due to user confusion. This vulnerability affects Firefox < 57.
How severe is CVE-2017-7838?: CVE-2017-7838 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2017-7838 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (71st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-7838?: CVE-2017-7838 affects Mozilla Firefox. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2017-7838?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2017-7838 published?: CVE-2017-7838 was published on 2018-06-11 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*

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