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CVE-2026-12289 Mozilla CVE debrief

CVE-2026-12289 is a privilege escalation vulnerability in the Graphics: WebRender component of Firefox. This issue was addressed in Firefox 152, Firefox ESR 140.12, and Firefox ESR 115.37.

Vendor
Mozilla
Product
Firefox
CVSS
HIGH 8.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-16
Original CVE updated
2026-07-15
Advisory published
2026-06-16
Advisory updated
2026-07-15

Who should care

Users of Firefox, especially those who handle sensitive data or require high security standards, should apply the updates to mitigate the risk of privilege escalation attacks.

Technical summary

The vulnerability allows for privilege escalation, potentially enabling an attacker to gain higher-level access within the application. The affected component is Graphics: WebRender in Firefox.

Defensive priority

High

Recommended defensive actions

  • Update to Firefox 152 or later
  • Update to Firefox ESR 140.12 or later
  • Update to Firefox ESR 115.37 or later

Evidence notes

The CVE was published and modified on June 16, 2026. References include Bugzilla issue 2023443 and Mozilla security advisories MFSA2026-57, MFSA2026-58, and MFSA2026-59.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-12289 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-12289

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

  • CVE-2026-12289 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-12289

    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.