CVE-2026-124539 PUBLISHED

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

Assigner: CPANSec
Reserved: 08.11.2026 Published: 14.11.2026 Updated: 14.11.2026

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.

Product Status

Package Collection https://cpan.org/modules
Package Name JSON-XS
Versions Default: unaffected
  • affected from 0 to 4.05 (excl.)

Solutions

Upgrade to JSON-XS 4.05 or later.

References

Problem Types

  • CWE-401 Missing Release of Memory after Effective Lifetime CWE