How severe is CVE-2020-15648?

CVE-2020-15648 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2020-15648 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (63rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-15648?

CVE-2020-15648 primarily affects Mozilla Firefox. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-15648?

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

When was CVE-2020-15648 published?

CVE-2020-15648 was published on 2020-08-10 and last updated on 2026-06-17.

CVE-2020-15648

CVE-2020-15648 is a medium-severity vulnerability in Mozilla Firefox with a CVSS 3.x base score of 6.5. 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-1021.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.3
EPSS exploit prediction: 1% (63rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-1021
Affected product: Mozilla Firefox
Published: 2020-08-10
Last modified: 2026-06-17

Description

Using object or embed tags, it was possible to frame other websites, even if they disallowed framing using the X-Frame-Options header. This vulnerability affects Thunderbird < 78 and Firefox < 78.0.2.

Frequently asked questions

What is CVE-2020-15648?: Using object or embed tags, it was possible to frame other websites, even if they disallowed framing using the X-Frame-Options header. This vulnerability affects Thunderbird < 78 and Firefox < 78.0.2.
How severe is CVE-2020-15648?: CVE-2020-15648 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2020-15648 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (63rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-15648?: CVE-2020-15648 primarily affects Mozilla Firefox. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-15648?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-15648 published?: CVE-2020-15648 was published on 2020-08-10 and last updated on 2026-06-17.

References

Affected products (2)

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

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