How severe is CVE-2026-12316?

CVE-2026-12316 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2026-12316 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (16th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-12316?

CVE-2026-12316 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-2026-12316?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2026-12316 have an EU (EUVD) identifier?

Yes. CVE-2026-12316 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-37107.

When was CVE-2026-12316 published?

CVE-2026-12316 was published on 2026-06-16 and last updated on 2026-06-17.

CVE-2026-12316

CVE-2026-12316 is a critical-severity vulnerability in Mozilla Firefox with a CVSS 3.x base score of 9.1. 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-693.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
EPSS exploit prediction: 0% (16th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-37107
Weakness: CWE-693
Affected product: Mozilla Firefox
Published: 2026-06-16
Last modified: 2026-06-17

Description

Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 152 and Thunderbird 152.

Frequently asked questions

What is CVE-2026-12316?: Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 152 and Thunderbird 152.
How severe is CVE-2026-12316?: CVE-2026-12316 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2026-12316 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (16th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-12316?: CVE-2026-12316 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-2026-12316?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-12316 have an EU (EUVD) identifier?: Yes. CVE-2026-12316 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-37107.
When was CVE-2026-12316 published?: CVE-2026-12316 was published on 2026-06-16 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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