To skip a leading 3-byte UTF-8 BOM, decode_json() advances the input scalar's string pointer past the mark with SvPV_set() and restores it only on the normal return path. When decoding aborts through a Perl exception, for example a filter_json_object callback that croaks, the restore is skipped and the scalar is left with its string pointer offset into its own buffer and a shortened length.
When that scalar is later freed, the allocator receives an invalid pointer and the interpreter aborts. A single BOM prefixed document decoded with a throwing filter callback crashes any caller.
No advisories yet.
Solution
Upgrade to Cpanel::JSON::XS 4.41 or later.
Workaround
No workaround given by the vendor.
Wed, 03 Jun 2026 18:30:00 +0000
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| Metrics |
cvssV3_1
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Wed, 03 Jun 2026 11:15:00 +0000
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Wed, 03 Jun 2026 04:45:00 +0000
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| First Time appeared |
Rurban
Rurban cpanel::json::xs |
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| Vendors & Products |
Rurban
Rurban cpanel::json::xs |
Wed, 03 Jun 2026 02:30:00 +0000
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| Description | Cpanel::JSON::XS versions before 4.41 for Perl allow denial of service via UTF-8 BOM prefixed input when a decode filter callback throws. To skip a leading 3-byte UTF-8 BOM, decode_json() advances the input scalar's string pointer past the mark with SvPV_set() and restores it only on the normal return path. When decoding aborts through a Perl exception, for example a filter_json_object callback that croaks, the restore is skipped and the scalar is left with its string pointer offset into its own buffer and a shortened length. When that scalar is later freed, the allocator receives an invalid pointer and the interpreter aborts. A single BOM prefixed document decoded with a throwing filter callback crashes any caller. | |
| Title | Cpanel::JSON::XS versions before 4.41 for Perl allow denial of service via UTF-8 BOM prefixed input when a decode filter callback throws | |
| Weaknesses | CWE-755 CWE-763 |
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| References |
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Projects
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Status: PUBLISHED
Assigner: CPANSec
Published:
Updated: 2026-06-03T15:58:49.426Z
Reserved: 2026-05-25T18:54:26.396Z
Link: CVE-2026-9516
Updated: 2026-06-03T09:35:39.521Z
Status : Received
Published: 2026-06-03T01:16:23.430
Modified: 2026-06-03T18:16:30.357
Link: CVE-2026-9516
No data.
OpenCVE Enrichment
Updated: 2026-06-03T19:30:36Z