CVE-2026-124539

JSON::XS versions before 4.05 for Perl leak the decoded key of an object rejected for a missing colon in decode_hv

Published Nov 14, 2026 CVSS n/a EPSS n/a KEV · Not listed
Description
JSON::XS versions before 4.05 for Perl leak the decoded key of an object rejected for a missing colon in decode_hv.

Unless it is short plain ASCII, a quoted key is decoded into a new scalar. Nothing frees that scalar when the object is rejected for a missing ':' after the key.

A process that keeps running after a failed decode retains one key per rejected document, with its size chosen by the sender. Repeated requests exhaust process memory.

Remediation

Vendor Solution

Upgrade to JSON-XS 4.05 or later.

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
Type Values Removed Values Added
Description JSON::XS versions before 4.05 for Perl leak the decoded key of an object rejected for a missing colon in decode_hv. Unless it is short plain ASCII, a quoted key is decoded into a new scalar. Nothing frees that scalar when the object is rejected for a missing ':' after the key. A process that keeps running after a failed decode retains one key per rejected document, with its size chosen by the sender. Repeated requests exhaust process memory.
Title JSON::XS versions before 4.05 for Perl leak the decoded key of an object rejected for a missing colon in decode_hv
Weaknesses CWE-401
References

Subscriptions

No data.

Weaknesses

Sources

Status
PUBLISHED
Assigner
CPANSec
Published
Updated
Nov 14, 2026, 11:52 AM
Reserved
Nov 8, 2026, 12:32 PM
Status
Received
Published
Nov 14, 2026, 12:17 PM
Modified
Nov 14, 2026, 12:17 PM