How severe is CVE-2019-9802?

CVE-2019-9802 has a CVSS 3.x base score of 7.5, rated high 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 none.

Is CVE-2019-9802 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (62nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2019-9802?

CVE-2019-9802 affects Mozilla Firefox. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2019-9802?

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-2019-9802 published?

CVE-2019-9802 was published on 2019-04-26 and last updated on 2026-06-17.

CVE-2019-9802

CVE-2019-9802 is a high-severity vulnerability in Mozilla Firefox with a CVSS 3.x base score of 7.5. 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

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (62nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-125
Affected product: Mozilla Firefox
Published: 2019-04-26
Last modified: 2026-06-17

Description

If a Sandbox content process is compromised, it can initiate an FTP download which will then use a child process to render the downloaded data. The downloaded data can then be passed to the Chrome process with an arbitrary file length supplied by an attacker, bypassing sandbox protections and allow for a potential memory read of adjacent data from the privileged Chrome process, which may include sensitive data. This vulnerability affects Firefox < 66.

Frequently asked questions

What is CVE-2019-9802?: If a Sandbox content process is compromised, it can initiate an FTP download which will then use a child process to render the downloaded data. The downloaded data can then be passed to the Chrome process with an arbitrary file length supplied by an attacker, bypassing sandbox protections and allow for a potential memory read of adjacent data from the privileged Chrome process, which may include sensitive data. This vulnerability affects Firefox < 66.
How severe is CVE-2019-9802?: CVE-2019-9802 has a CVSS 3.x base score of 7.5, rated high 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 none.
Is CVE-2019-9802 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (62nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-9802?: CVE-2019-9802 affects Mozilla Firefox. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2019-9802?: 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-2019-9802 published?: CVE-2019-9802 was published on 2019-04-26 and last updated on 2026-06-17.

References

Affected products (1)

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

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