Cpanel::JSON::XS versions before 4.80 for Perl allow memory exhaustion by encoding exponent notation as full decimal digits under allow_bignum

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-110676
StatePUBLISHED
AssignerCPANSec
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-10-19 19:17:21 UTC
Updated2026-10-19 20:50:17 UTC
DescriptionCpanel::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.

Risk And Classification

Problem Types: CWE-405 | CWE-405 CWE-405 Asymmetric Resource Consumption (Amplification)

References

ReferenceSourceLinkTags
github.com/rurban/Cpanel-JSON-XS/commit/996ab96972b967a917536d291947b5f3... 9b29abf9-4ab0-4765-b253-1875cd9b441e github.com
metacpan.org/release/RURBAN/Cpanel-JSON-XS-4.80/changes 9b29abf9-4ab0-4765-b253-1875cd9b441e metacpan.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Additional Advisory Data

SourceTimeEvent
CNA2026-10-14T00:00:00.000ZVersion 4.80 released with fix.

Solutions

CNA: Upgrade to Cpanel-JSON-XS 4.80 or later.

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