Renderer code execution via stale slots pointer
Published Jun 2, 2026 · Updated Jun 2, 2026
JIT miscompilation in Firefox before 151.0.3 allows remote attackers to execute code in the renderer by opening a crafted webpage. SpiderMonkey's MObjectToIterator marks a mutation-capable operation as read-only, so global value numbering reuses a dynamic-slots pointer after lazy property resolution reallocates and frees its buffer. Opening attacker-controlled content is required, and the documented primitive grants memory read and write within the sandboxed renderer process.
Summary
What happened
JIT miscompilation in Firefox before 151.0.3 allows remote attackers to execute code in the renderer by opening a crafted webpage. SpiderMonkey's MObjectToIterator marks a mutation-capable operation as read-only, so global value numbering reuses a dynamic-slots pointer after lazy property resolution reallocates and frees its buffer. Opening attacker-controlled content is required, and the documented primitive grants memory read and write within the sandboxed renderer process.
The record
- CVE
- CVE-2026-10702
- Published
- Jun 2, 2026
- Updated
- Jun 2, 2026
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-843, CWE-733, T1203, T1189
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 2, 2026CVE publishedPublication date reported by the CVE source.
- Jun 2, 2026Record updatedLatest update available in the CVE record.
- Jul 10, 2026Exploitation reportedNebula Security Firefox and Tor Browser demonstrations
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.
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
- IonStack Firefox renderer exploitfunctional · unverified
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Reported exploitation
- Nebula Security Firefox and Tor Browser demonstrationsreported exploitation
Technologies
Your stack
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Your stack
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