Memory corruption via empty GC slices access
Published Sep 16, 2025 · Updated Sep 16, 2025
Buffer overrun in the JavaScript garbage collector in Mozilla Firefox, Firefox ESR, and Thunderbird allows remote attackers to corrupt memory. The GC statistics path calls Vector::back() from Statistics::recordParallelPhase after an out-of-memory abort leaves the slices vector empty. Triggering requires an out-of-memory event at a particular point and a later operation with difficult timing; in Thunderbird, scripting is disabled while reading mail, limiting exposure to browser-like contexts.
Summary
What happened
Buffer overrun in the JavaScript garbage collector in Mozilla Firefox, Firefox ESR, and Thunderbird allows remote attackers to corrupt memory. The GC statistics path calls Vector::back() from Statistics::recordParallelPhase after an out-of-memory abort leaves the slices vector empty. Triggering requires an out-of-memory event at a particular point and a later operation with difficult timing; in Thunderbird, scripting is disabled while reading mail, limiting exposure to browser-like contexts.
The record
- CVE
- CVE-2025-10532
- Published
- Sep 16, 2025
- Updated
- Sep 16, 2025
- Vendor
- Mozilla
- Product
- Firefox
- Classifications
- CWE-754, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 16, 2025CVE publishedPublication date reported by the CVE source.
- Sep 16, 2025Record 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 <143
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
- Mozilla JavaScript GC crash testcaseproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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