Process crash via wrapped JSON string length
Published Jun 30, 2026 · Updated Jul 1, 2026
Integer overflow in Oj before 3.17.2 allows remote attackers to crash a process by supplying a JSON string longer than 2 GB. In read_escaped_str, the parser narrows the string length to a 32-bit int, then buf_append_string converts the wrapped negative value to size_t and passes it to memcpy. Exploitation requires an application to submit the oversized string to Oj.load; the resulting out-of-bounds copy corrupts heap memory and interrupts that process.
Summary
What happened
Integer overflow in Oj before 3.17.2 allows remote attackers to crash a process by supplying a JSON string longer than 2 GB. In read_escaped_str, the parser narrows the string length to a 32-bit int, then buf_append_string converts the wrapped negative value to size_t and passes it to memcpy. Exploitation requires an application to submit the oversized string to Oj.load; the resulting out-of-bounds copy corrupts heap memory and interrupts that process.
The record
- CVE
- CVE-2026-54903
- Published
- Jun 30, 2026
- Updated
- Jul 1, 2026
- Vendor
- Peter Ohler
- Product
- Oj
- Classifications
- CWE-190, T1499
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 30, 2026CVE publishedPublication date reported by the CVE source.
- Jul 1, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 3.17.2
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.
Public exploit references
- GHSA oversized-string reproductionproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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