# CVE-2026-74985: Mozilla Firefox privilege escalation in Enterprise Policies

Source: https://junglewise.ai/threats/cve-2026-74985-mozilla-firefox-privilege-escalation-in-enterprise-policies  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-18. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-74985 · Severity: critical · CVSS 9.8 · Published 2026-08-18

Firefox, Thunderbird, and their ESR variants contain a privilege escalation vulnerability in the Enterprise Policies component that could allow an attacker to escalate their access level on an affected system. An exploit of this vulnerability could enable unauthorized access to sensitive data, system compromise, or lateral movement within a corporate network.

Technologies: [Mozilla Firefox](https://junglewise.ai/threats/technologies/firefox), [Mozilla Firefox ESR](https://junglewise.ai/threats/technologies/firefox-esr), [Mozilla Thunderbird](https://junglewise.ai/threats/technologies/thunderbird), [Mozilla Thunderbird ESR](https://junglewise.ai/threats/technologies/thunderbird-esr). Vendors: [Mozilla](https://junglewise.ai/threats/vendors/mozilla).

## Quick answers

**Is CVE-2026-74985 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-74985 being exploited in the wild.

**How severe is CVE-2026-74985?** Critical severity, with a CVSS score of 9.8, published 18 August 2026.

**Which products and versions are affected?** Mozilla Firefox before 154; Mozilla Firefox ESR before 153.1; Mozilla Thunderbird before 154; Mozilla Thunderbird ESR before 153.1.

**Is there a fix for CVE-2026-74985?** A patch was published on 2026-08-18: Fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-74985 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-74985?** Check whether you run Mozilla Firefox, Mozilla Firefox ESR, Mozilla Thunderbird or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

CVE-2026-74985 is a privilege escalation vulnerability in the Enterprise Policies component affecting Firefox, Firefox ESR, Thunderbird, and Thunderbird ESR. The vulnerability allows an attacker to escalate privileges through improper handling of policy enforcement mechanisms. The exact attack vector and preconditions are not publicly detailed, though the high CVSS score (9.8) indicates network accessibility without authentication or user interaction required. The vulnerability has been patched in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.

## Affected products

- Mozilla Firefox before 154
- Mozilla Firefox ESR before 153.1
- Mozilla Thunderbird before 154
- Mozilla Thunderbird ESR before 153.1

## Timeline

- 2026-08-18: disclosed: Vulnerability disclosed by Mozilla
- 2026-08-18: patched: Fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1

## References

- [https://bugzilla.mozilla.org/show_bug.cgi?id=2059825](https://bugzilla.mozilla.org/show_bug.cgi?id=2059825)
- [https://www.mozilla.org/security/advisories/mfsa2026-74/](https://www.mozilla.org/security/advisories/mfsa2026-74/)

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