Buffer under-allocation via overflowed capacity calculation
Published Jan 27, 2026 · Updated Jan 27, 2026
Integer overflow in foxinmy weixin4j 1.10.2 and earlier allows remote attackers to trigger buffer under-allocation through oversized input. CharArrayBuffer.ensureCapacity adds the current length and required capacity with unchecked 32-bit integer arithmetic, so the sum can wrap before buffer expansion. Exploitation requires a consuming application to pass attacker-controlled sizing data large enough to overflow the sum; no public source demonstrates a consequence beyond failed or excessive allocation.
Summary
What happened
Integer overflow in foxinmy weixin4j 1.10.2 and earlier allows remote attackers to trigger buffer under-allocation through oversized input. CharArrayBuffer.ensureCapacity adds the current length and required capacity with unchecked 32-bit integer arithmetic, so the sum can wrap before buffer expansion. Exploitation requires a consuming application to pass attacker-controlled sizing data large enough to overflow the sum; no public source demonstrates a consequence beyond failed or excessive allocation.
The record
- CVE
- CVE-2026-24819
- Published
- Jan 27, 2026
- Updated
- Jan 27, 2026
- Vendor
- foxinmy
- Product
- weixin4j
- Classifications
- CWE-1325, CAPEC-130, T1499.003
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 27, 2026CVE publishedPublication date reported by the CVE source.
- Jan 27, 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?
Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.
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
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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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