How severe is CVE-2019-11761?

CVE-2019-11761 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2019-11761 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2019-11761?

CVE-2019-11761 primarily affects Mozilla Firefox. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2019-11761?

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

When was CVE-2019-11761 published?

CVE-2019-11761 was published on 2020-01-08 and last updated on 2026-06-17.

CVE-2019-11761

CVE-2019-11761 is a medium-severity vulnerability in Mozilla Firefox with a CVSS 3.x base score of 5.4. 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-362.

Key facts

Severity: Medium (CVSS 3.x base score 5.4)
CVSS v2: 5.8
EPSS exploit prediction: 1% (52nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-362
Affected product: Mozilla Firefox
Published: 2020-01-08
Last modified: 2026-06-17

Description

By using a form with a data URI it was possible to gain access to the privileged JSONView object that had been cloned into content. Impact from exposing this object appears to be minimal, however it was a bypass of existing defense in depth mechanisms. This vulnerability affects Firefox < 70, Thunderbird < 68.2, and Firefox ESR < 68.2.

Frequently asked questions

What is CVE-2019-11761?: By using a form with a data URI it was possible to gain access to the privileged JSONView object that had been cloned into content. Impact from exposing this object appears to be minimal, however it was a bypass of existing defense in depth mechanisms. This vulnerability affects Firefox < 70, Thunderbird < 68.2, and Firefox ESR < 68.2.
How severe is CVE-2019-11761?: CVE-2019-11761 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2019-11761 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-11761?: CVE-2019-11761 primarily affects Mozilla Firefox. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2019-11761?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2019-11761 published?: CVE-2019-11761 was published on 2020-01-08 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*

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