How severe is CVE-2026-0887?

CVE-2026-0887 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2026-0887 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-0887?

CVE-2026-0887 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-2026-0887?

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

Does CVE-2026-0887 have an EU (EUVD) identifier?

Yes. CVE-2026-0887 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-2078.

When was CVE-2026-0887 published?

CVE-2026-0887 was published on 2026-01-13 and last updated on 2026-06-17.

CVE-2026-0887

CVE-2026-0887 is a medium-severity vulnerability in Mozilla Firefox with a CVSS 3.x base score of 4.3. 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-497.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
EPSS exploit prediction: 0% (20th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-2078
Weakness: CWE-497
Affected product: Mozilla Firefox
Published: 2026-01-13
Last modified: 2026-06-17

Description

Clickjacking issue, information disclosure in the PDF Viewer component. This vulnerability was fixed in Firefox 147, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7.

Frequently asked questions

What is CVE-2026-0887?: Clickjacking issue, information disclosure in the PDF Viewer component. This vulnerability was fixed in Firefox 147, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7.
How severe is CVE-2026-0887?: CVE-2026-0887 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2026-0887 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-0887?: CVE-2026-0887 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-2026-0887?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-0887 have an EU (EUVD) identifier?: Yes. CVE-2026-0887 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-2078.
When was CVE-2026-0887 published?: CVE-2026-0887 was published on 2026-01-13 and last updated on 2026-06-17.

References

Affected products (4)

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

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