Description
Use-after-free in the JavaScript: GC component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
Published: 2026-10-27
Score: n/a
EPSS: n/a
KEV: No
Impact: Remote code execution
Action: Immediate Patch
AI Analysis

Impact

The vulnerability involves a use‑after‑free condition within the JavaScript garbage‑collector component of Firefox. This flaw can corrupt memory, potentially allowing an attacker to execute arbitrary code or influence the program flow. The vulnerability was fixed in Firefox 159 and the ESR 153.6 release.

Affected Systems

All Mozilla Firefox browsers running versions older than 159, including the extended support release prior to 153.6, are susceptible. This inference is drawn from the advisory indicating the fix in Firefox 159 and ESR 153.6, so users of these versions remain at risk until they upgrade to the patched releases.

Risk and Exploitability

No EPSS score is available, and the vulnerability is not listed in the CISA KEV catalog, but the use‑after‑free nature implies a high exploitation potential if an attacker can deliver malicious JavaScript content. The lack of an EPSS score does not diminish the seriousness; any exploitation would likely enable remote code execution on the victim machine.

Generated by OpenCVE AI on October 27, 2026 at 18:03 UTC.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Upgrade Mozilla Firefox to version 159 or newer, or to the ESR 153.6 or newer release.
  • Disable or restrict JavaScript execution on untrusted sites, or employ a strict content security policy to limit script usage.
  • Enable automatic updates or regularly check for and install browser updates to maintain protection against related vulnerabilities.

Generated by OpenCVE AI on October 27, 2026 at 18:03 UTC.

Tracking

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Advisories

No advisories yet.

History

Tue, 27 Oct 2026 18:45:00 +0000

Type Values Removed Values Added
Description Use-after-free in the JavaScript: GC component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, and Thunderbird 159. Use-after-free in the JavaScript: GC component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
References

Tue, 27 Oct 2026 18:30:00 +0000

Type Values Removed Values Added
Description Use-after-free in the JavaScript: GC component. This vulnerability was fixed in Firefox 159 and Firefox ESR 153.6. Use-after-free in the JavaScript: GC component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, and Thunderbird 159.
Weaknesses CWE-416
References

Tue, 27 Oct 2026 14:15:00 +0000

Type Values Removed Values Added
Description Use-after-free in the JavaScript: GC component. This vulnerability was fixed in Firefox 159 and Firefox ESR 153.6.
Title Use-after-free in the JavaScript: GC component
References

Subscriptions

No data.

cve-icon MITRE

Status: PUBLISHED

Assigner: mozilla

Published:

Updated: 2026-10-27T18:28:47.667Z

Reserved: 2026-10-27T14:05:21.550Z

Link: CVE-2026-117909

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Deferred

Published: 2026-10-27T14:16:46.343

Modified: 2026-10-27T19:17:16.157

Link: CVE-2026-117909

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-27T18:15:06Z

Weaknesses