Handler on Duty: Johannes Ullrich
Threat Level: green
| Published | 2026-06-03 01:16:23 |
|---|---|
| Last Modified | 2026-06-03 01:16:23 |
| AKA | CVE-2026-9334 |
| Summary | Cpanel::JSON::XS versions before 4.41 for Perl allow type confusion via duplicate object keys when dupkeys_as_arrayref is enabled. decode_hv() collapses duplicate object keys into an array reference under dupkeys_as_arrayref. The branch reached for a duplicate key tests `SvTYPE (old_value) != SVt_RV && SvTYPE (SvRV (old_value)) != SVt_PVAV`, which evaluates SvRV(old_value) before establishing that old_value is a reference. When the existing value is a plain scalar rather than an array reference, a non-reference scalar is dereferenced as a reference. A caller decoding untrusted JSON with dupkeys_as_arrayref enabled is crashed, and the incompatible access follows a pointer taken from attacker controlled scalar contents. |
| Access Vector | Local | Adjacent | Network |
|---|---|---|---|
| Access Complexity | Low | Medium | High |
| Authentication | None | Single | Multiple |
| Confidentiality | None | Partial | Complete |
| Integrity | None | Partial | Complete |
| Availability | None | Partial | Complete |