Vulnerability in Rurban Cpanel\
CVE-2026-9516
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.006 (48.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 48th percentile — 48.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.006 · change: +0.003
Affected products
- Rurban Cpanel\ — versions \
- Rurban Cpanel::json::xs — versions 0
- Rurban Cpanel\:\:json\:\:xs
Weakness classification (CWE)
References
- 9b29abf9-4ab0-4765-b253-1875cd9b441e (Patch, patch)
- 9b29abf9-4ab0-4765-b253-1875cd9b441e (release-notes, Release Notes)
- af854a3a-2127-422b-91ae-364da2661108 (Patch, Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2026-9516?
- CVE-2026-9516 is a high-severity vulnerability in Rurban Cpanel\, classified under Improper Handling of Exceptional Conditions. CVSS score: 7.5/10. Published 2026-06-03.
- How severe is CVE-2026-9516?
- High severity. CVSS v3 base score is 7.5 out of 10.