CVE EVIDENCE REVIEW
ReviewCriticalEvidence review

CVE-2026-74938 evidence review

Mozilla Firefox, Thunderbird, firefox

Mitigation bypass in the JavaScript: GC component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.

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Evidence review

This record remains available for product and version identification, but it is not presented as a complete remediation procedure. Confirm the affected range and the supported fix in a direct vendor advisory before changing production systems.

ProductMozilla Firefox, Thunderbird, firefox
Affected versions< 153.1.0, < 154.0.0, < 154.0
Fixed versions153.1.0, 154.0.0, 154.0
Priority basisReview · CVSS 9.1 · EPSS -
01

Identify the product and installed version

Record whether Mozilla Firefox, Thunderbird, firefox is present, where it is installed, and which interfaces are exposed.

  • Record the product name, package or appliance identifier, and installed version.
  • Identify internet-facing, administrative, API, and internal access paths.
  • Preserve the pre-change configuration and relevant service logs.
02

Compare the affected range

Use the current record as an identification aid: < 153.1.0, < 154.0.0, < 154.0. Resolve incomplete inventory results before deciding that an asset is unaffected.

03

Verify the authoritative remediation source

Open the linked source material and locate a direct vendor advisory for this CVE. Confirm the supported fixed release and product-specific update path before making a production change.

Operational boundary

This page does not replace the vendor advisory, support contract, change-management process, or recovery plan. Do not infer that an asset is unaffected from an incomplete inventory query or a missing fixed-version field.