Process crash via overlong JSON numbers
Published Sep 8, 2025 · Updated Nov 4, 2025
Integer overflow in Cpanel::JSON::XS before 4.40 allows attackers to crash a Perl process by supplying crafted JSON. The json_atof_scan1 number parser uses incorrect digit-boundary comparisons for overlong numeric tokens, so its scan advances past the input buffer and reaches a segmentation fault. The module must decode attacker-controlled JSON; a process crash is demonstrated, while any additional impact remains unspecified.
Summary
What happened
Integer overflow in Cpanel::JSON::XS before 4.40 allows attackers to crash a Perl process by supplying crafted JSON. The json_atof_scan1 number parser uses incorrect digit-boundary comparisons for overlong numeric tokens, so its scan advances past the input buffer and reaches a segmentation fault. The module must decode attacker-controlled JSON; a process crash is demonstrated, while any additional impact remains unspecified.
The record
- CVE
- CVE-2025-40929
- Published
- Sep 8, 2025
- Updated
- Nov 4, 2025
- Vendor
- Reini Urban
- Product
- Cpanel::JSON::XS
- Classifications
- CWE-122, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 8, 2025CVE publishedPublication date reported by the CVE source.
- Nov 4, 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=0 <4.40
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What is affected?
Published CVSS scores
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Attacks
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Public exploit references
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Technologies
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Your stack
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