DOM Security mitigation bypass
Published Jan 13, 2026 · Updated Jan 13, 2026
Mitigation bypass in Mozilla Firefox and Firefox ESR allows remote attackers to bypass a DOM Security safeguard during browsing. Mozilla has not disclosed the affected safeguard or the DOM Security operation that mishandles attacker-controlled content. Normal browsing interaction is required; published assessments limit the measured impact to confidentiality and integrity, but no concrete consequence is public.
Summary
What happened
Mitigation bypass in Mozilla Firefox and Firefox ESR allows remote attackers to bypass a DOM Security safeguard during browsing. Mozilla has not disclosed the affected safeguard or the DOM Security operation that mishandles attacker-controlled content. Normal browsing interaction is required; published assessments limit the measured impact to confidentiality and integrity, but no concrete consequence is public.
The record
- CVE
- CVE-2026-0877
- Published
- Jan 13, 2026
- Updated
- Jan 13, 2026
- Vendor
- Mozilla
- Product
- Firefox
- Classifications
- CWE-693
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 13, 2026CVE publishedPublication date reported by the CVE source.
- Jan 13, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=unspecified <147
What conditions does exploitation require?
What is affected?
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
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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