CVE-2026-109712

HIGH

Published Oct 13, 2026 Modified Oct 16, 2026 CWE-908

Description

Sandbox escape due to uninitialized memory in the Graphics component. This vulnerability was fixed in Firefox 158, Firefox ESR 115.43, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.

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CVSS v3.1 Score

7.1

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L

EPSS — Exploit Prediction

0.0022

Probability of exploitation

0.13%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-908 CWE-908

References

Other References

https://bugzilla.mozilla.org/show_bug.cgi?id=2068420 https://www.mozilla.org/security/advisories/mfsa2026-106/ https://www.mozilla.org/security/advisories/mfsa2026-107/ https://www.mozilla.org/security/advisories/mfsa2026-108/ https://www.mozilla.org/security/advisories/mfsa2026-109/ https://www.mozilla.org/security/advisories/mfsa2026-110/

Frequently Asked Questions

What is CVE-2026-109712? +

Sandbox escape due to uninitialized memory in the Graphics component. This vulnerability was fixed in Firefox 158, Firefox ESR 115.43, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5. It has a CVSS v3.1 base score of 7.1 (HIGH).

How severe is CVE-2026-109712? +

CVE-2026-109712 has a CVSS v3.1 score of 7.1 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0022, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-109712? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.