Skip to content

CVE-2026-74964

Mozilla Firefox integer overflow

9.8 CRITICALEPSS 0.68%
  1. Published18 Aug 2026

Description

Integer overflow in the Graphics component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

Mozilla Firefox≥ 141.0.0 < 153.1.0 · < 140.14.0
Mozilla Thunderbird≥ 141.0 < 153.1.0 · < 140.14.0

Frequently asked

Is CVE-2026-74964 being actively exploited?

CVE-2026-74964 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.68%.

How severe is CVE-2026-74964?

CVE-2026-74964 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 0.68% probability of exploitation.

Which products are affected by CVE-2026-74964?

Affected products include Mozilla Firefox, Mozilla Thunderbird.

How do I fix CVE-2026-74964?

Upgrade affected software to a fixed version, for example Mozilla Firefox 153.1.0, Mozilla Thunderbird 153.1.0 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-74964 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

Get Patch this first every Monday

Five vulnerabilities that matter this week, ranked on real exploitation. Plain language, one email, no spam.

You can unsubscribe with one click from every issue. We handle your details as described in our privacy policy.

Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.