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PatchSiren cyber security CVE debrief

CVE-2026-12306 Mozilla CVE debrief

A memory safety bug was fixed in Firefox 152 and Firefox ESR 140.12. This vulnerability was published on [CVE.org](resourceLinkAnnotations:cve-org) and additional details can be found on [NVD](resourceLinkAnnotations:nvd).

Vendor
Mozilla
Product
Firefox
CVSS
MEDIUM 5.3
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-16
Original CVE updated
2026-06-18
Advisory published
2026-06-16
Advisory updated
2026-06-18

Who should care

Users of Firefox 152 and Firefox ESR 140.12 should ensure they have updated to the latest versions to mitigate this vulnerability.

Technical summary

A memory safety bug was fixed in Firefox 152 and Firefox ESR 140.12.

Defensive priority

High

Recommended defensive actions

  • Update to Firefox 152 or Firefox ESR 140.12

Evidence notes

The CVE was published on 2026-06-16T13:16:30.833Z and has been associated with Mozilla.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-12306 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-12306

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-12306 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-12306

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.