Privilege escalation in DOM Workers
Published May 19, 2026 · Updated May 19, 2026
Privilege escalation in Firefox before 151, Firefox ESR before 140.11, and Thunderbird before 151 grants remote attackers elevated access. Mozilla identifies the affected locus only as DOM: Workers and has not published the incorrect worker operation or privilege boundary involved. User interaction with attacker-controlled browser content is required; Thunderbird ESR before 140.11 is also affected, but mail reading disables scripting.
Summary
What happened
Privilege escalation in Firefox before 151, Firefox ESR before 140.11, and Thunderbird before 151 grants remote attackers elevated access. Mozilla identifies the affected locus only as DOM: Workers and has not published the incorrect worker operation or privilege boundary involved. User interaction with attacker-controlled browser content is required; Thunderbird ESR before 140.11 is also affected, but mail reading disables scripting.
The record
- CVE
- CVE-2026-8955
- Published
- May 19, 2026
- Updated
- May 19, 2026
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-269, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 19, 2026CVE publishedPublication date reported by the CVE source.
- May 19, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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What is affected?
Affected products and versions are unavailable in this record.
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
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
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Technologies
Your stack
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Your stack
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