CVE-2026-110676
Cpanel::JSON::XS versions before 4.80 for Perl allow memory exhaustion by encoding exponent notation as full decimal digits under allow_bignum
- State
- Published
- Severity
- 7.5 High
- Published
- Oct 19, 2026
- Updated
- Oct 29, 2026
- Reserved
- Oct 14, 2026
Description
Cpanel::JSON::XS versions before 4.80 for Perl allow memory exhaustion by encoding exponent notation as full decimal digits under allow_bignum.
With allow_bignum, a JSON number with a fraction or exponent decodes to a Math::BigFloat, which stores the exponent separately and so decodes cheaply. Encoding it untyped or as JSON_TYPE_FLOAT writes the plain decimal form with one digit per unit of exponent. Nothing bounds the exponent, so the 12-byte text [1e30000000] encodes to 30 MB.
Untrusted JSON decoded with allow_bignum and encoded again can exhaust memory and CPU.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 7.5 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | CISA-ADP |
Weaknesses
- CWE-405 Asymmetric Resource Consumption (Amplification)
Affected Products
| Product | Versions |
|---|---|
Cpanel-JSON-XS |
|
References
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