Unspecified impact via XML_ParseBuffer integer overflow
Published Jun 21, 2026 · Updated Jun 21, 2026
Integer overflow in XML_ParseBuffer in Expat Project libexpat before 2.8.2 allows attackers to trigger unspecified impact via unspecified vectors. XML_ParseBuffer omits an integer-overflow check present in XML_Parse before operating on its internal buffer length, allowing size arithmetic to wrap. Reachability requires a consuming application to use XML_ParseBuffer with attacker-influenced parsing input; the published record does not bound the post-overflow consequence.
Summary
What happened
Integer overflow in XML_ParseBuffer in Expat Project libexpat before 2.8.2 allows attackers to trigger unspecified impact via unspecified vectors. XML_ParseBuffer omits an integer-overflow check present in XML_Parse before operating on its internal buffer length, allowing size arithmetic to wrap. Reachability requires a consuming application to use XML_ParseBuffer with attacker-influenced parsing input; the published record does not bound the post-overflow consequence.
The record
- CVE
- CVE-2026-56406
- Published
- Jun 21, 2026
- Updated
- Jun 21, 2026
- Vendor
- Expat Project
- Product
- libexpat
- Classifications
- Unavailable
- Attack vector
- Unavailable
- Privileges
- Unavailable
Timeline
How it unfolded
- Jun 21, 2026CVE publishedPublication date reported by the CVE source.
- Jun 21, 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=0 <2.8.2
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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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
No sourced classifications are available.
Public exploit references
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Technologies
Your stack
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Your stack
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