# CVE-2026-9516

## Summary

- **CVE ID:** CVE-2026-9516
- **Severity:** HIGH
- **CVSS Score:** 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
- **CWE:** CWE-763, CWE-755
- **Published:** Jun 3, 2026
- **Last Modified:** Jun 3, 2026

## 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.

## Affected Products

- RURBAN — Cpanel::JSON::XS (0)

## References

- [CNA](https://github.com/rurban/Cpanel-JSON-XS/commit/dfe1b41a36caba51dc12a2917fe50285d1ffaa7b.patch)
- [CNA](https://metacpan.org/release/RURBAN/Cpanel-JSON-XS-4.41/changes)
- [CVE](http://www.openwall.com/lists/oss-security/2026/06/03/5)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.36%
- **EPSS Percentile:** 29.3

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._