Privilege escalation
Published Aug 18, 2026 · Updated Aug 21, 2026
Privilege escalation in Firefox and Thunderbird before 154 and ESR before 153.1 allows remote attackers to gain elevated privileges. Mozilla has not published which Request Handling operation mishandles crafted input or how that operation crosses a privilege boundary. Exploitation requires user interaction with attacker-controlled content; Thunderbird mail reading normally disables scripting, and no more specific consequence is disclosed.
Summary
What happened
Privilege escalation in Firefox and Thunderbird before 154 and ESR before 153.1 allows remote attackers to gain elevated privileges. Mozilla has not published which Request Handling operation mishandles crafted input or how that operation crosses a privilege boundary. Exploitation requires user interaction with attacker-controlled content; Thunderbird mail reading normally disables scripting, and no more specific consequence is disclosed.
The record
- CVE
- CVE-2026-74955
- Published
- Aug 18, 2026
- Updated
- Aug 21, 2026
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-551
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 18, 2026CVE publishedPublication date reported by the CVE source.
- Aug 21, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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