Browser-process memory disclosure via unchecked subimage bounds
Published Jan 13, 2026 · Updated Jan 13, 2026
Out-of-bounds read in Mozilla Firefox before 147 and Firefox ESR before 115.32 or 140.7 allows attackers to read browser memory via drawing data. GetCairoSurfaceForSourceSurface accepts an attacker-controlled subimage rectangle without confirming that it lies inside the source surface, and CreateSubImageForData derives a pointer from its unchecked offset and size. A compromised content process can send the drawing parameters across the sandbox boundary; the demonstrated consequence is an arbitrary-size, arbitrary-offset read from the browser process.
Summary
What happened
Out-of-bounds read in Mozilla Firefox before 147 and Firefox ESR before 115.32 or 140.7 allows attackers to read browser memory via drawing data. GetCairoSurfaceForSourceSurface accepts an attacker-controlled subimage rectangle without confirming that it lies inside the source surface, and CreateSubImageForData derives a pointer from its unchecked offset and size. A compromised content process can send the drawing parameters across the sandbox boundary; the demonstrated consequence is an arbitrary-size, arbitrary-offset read from the browser process.
The record
- CVE
- CVE-2026-0886
- Published
- Jan 13, 2026
- Updated
- Jan 13, 2026
- Vendor
- Mozilla
- Product
- Firefox
- Classifications
- CWE-119, T1068
- 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?
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- Affected versionversion=unspecified <147
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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