Description
Mojo::JSON versions before 9.47 for Perl allow memory exhaustion via unbounded recursion in the pure-Perl decoder. The pure-Perl decode path (`_decode_value` dispatching to `_decode_array` and `_decode_object`) recurses with no depth limit, so a small deeply nested JSON document can consume excessive memory. This path is the default when Cpanel::JSON::XS is not installed or `MOJO_NO_JSON_XS=1` is set; the Cpanel::JSON::XS fast path is not affected. Any caller that decodes an untrusted JSON body, for example `Mojo::Message::json` reached through `$c->req->json`, can exhaust process memory and cause denial of service.
Problem types
CWE-674 Uncontrolled Recursion
Product status
Any version before 9.47
Timeline
| 2026-07-05: | Version 9.47 released with fix. |
References
www.openwall.com/lists/oss-security/2026/07/06/2
github.com/...cc38b0554275c4d84f6b8b49bcbbc1bec2068fe1.patch
metacpan.org/release/SRI/Mojolicious-9.47/changes