How severe is CVE-2026-3846?

CVE-2026-3846 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-2026-3846 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-3846?

CVE-2026-3846 affects Mozilla Firefox. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-3846?

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

Does CVE-2026-3846 have an EU (EUVD) identifier?

Yes. CVE-2026-3846 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-10504.

When was CVE-2026-3846 published?

CVE-2026-3846 was published on 2026-03-10 and last updated on 2026-06-17.

CVE-2026-3846

CVE-2026-3846 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-346.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
EPSS exploit prediction: 0% (2nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-10504
Weakness: CWE-346
Affected product: Mozilla Firefox
Published: 2026-03-10
Last modified: 2026-06-17

Description

Same-origin policy bypass in the CSS Parsing and Computation component. This vulnerability was fixed in Firefox 148.0.2.

Frequently asked questions

What is CVE-2026-3846?: Same-origin policy bypass in the CSS Parsing and Computation component. This vulnerability was fixed in Firefox 148.0.2.
How severe is CVE-2026-3846?: CVE-2026-3846 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-2026-3846 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-3846?: CVE-2026-3846 affects Mozilla Firefox. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-3846?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-3846 have an EU (EUVD) identifier?: Yes. CVE-2026-3846 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-10504.
When was CVE-2026-3846 published?: CVE-2026-3846 was published on 2026-03-10 and last updated on 2026-06-17.

References

Affected products (1)

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

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