Vulnerability 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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Rurban | Cpanel\ | < 4.41, \ |
Related Weaknesses (CWE)
References
- https://github.com/rurban/Cpanel-JSON-XS/commit/dfe1b41a36caba51dc12a2917fe50285Patch
- https://metacpan.org/release/RURBAN/Cpanel-JSON-XS-4.41/changesRelease Notes
- http://www.openwall.com/lists/oss-security/2026/06/03/5Mailing ListPatchThird Party Advisory
FAQ
What is CVE-2026-9516?
CVE-2026-9516 is a vulnerability with a CVSS score of 7.5 (HIGH). 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 th...
How severe is CVE-2026-9516?
CVE-2026-9516 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-9516?
Check the references section above for vendor advisories and patch information. Affected products include: Rurban Cpanel\.