CVE-2026-74988: Internally found bugs fixed in Firefox ESR 153.1 and Firefox 154

Published Aug 18, 2026
·
Updated

Internally found bugs present in Firefox ESR 153.0 and Firefox 153. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited.

Affected Software

4 affected componentsFixes available
Mozilla Firefox ESR>=153.0<=153.0
Mozilla Firefox>=154<=154
Mozilla Firefox<154
154
Mozilla Firefox ESR<153.1
153.1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 154
  2. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 153.1
  3. Upgrade

    Upgrade Firefox ESR 153 to a version that resolves this vulnerability.

    Fixed in 153.1
  4. Upgrade

    Upgrade Firefox 154 to a version that resolves this vulnerability.

    Fixed in 154

Event History

Aug 18, 2026
CVE Published
via Mozilla·12:00 AM
Data Sourced
via Mozilla·12:00 AM
DescriptionSeverityAffected Software
Updated
via Mozilla·12:00 AM
Affected Software
CVE Published
via MITRE·12:23 PM
Data Sourced
via MITRE·12:23 PM
Description

Parent advisories

This vulnerability appears in the following advisories.

Frequently Asked Questions

1

Which Firefox releases need to be updated?

Firefox 153 and Firefox ESR 153.0 are affected. The fixes are included in Firefox 154 and Firefox ESR 153.1.

2

Is exploitation known to be practical?

Mozilla reports evidence of memory corruption or other security-relevant defects in some of the underlying bugs and presumes that some could be exploitable with sufficient effort. The provided information does not identify a specific exploit path or attacker prerequisites.

Contact

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