CVE-2026-9516Network attack vector

Process abort via unrestored BOM pointer

Published Jun 3, 2026 · Updated Jun 3, 2026

Denial of service in Cpanel::JSON::XS before 4.41 allows attackers to abort a calling Perl process via BOM-prefixed JSON. In decode_json(), BOM handling advances the input scalar's pointer with SvPV_set(), but an exception from a decode filter bypasses restoration and leaves a mid-allocation pointer. The caller must decode a BOM-prefixed document with a filter callback that throws; freeing the altered scalar then aborts the interpreter.

CVSS severity7.5
High
EPSS probability0.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Cpanel::JSON::XS before 4.41 allows attackers to abort a calling Perl process via BOM-prefixed JSON. In decode_json(), BOM handling advances the input scalar's pointer with SvPV_set(), but an exception from a decode filter bypasses restoration and leaves a mid-allocation pointer. The caller must decode a BOM-prefixed document with a filter callback that throws; freeing the altered scalar then aborts the interpreter.

The record

CVE
CVE-2026-9516
Published
Jun 3, 2026
Updated
Jun 3, 2026
Vendor
Reini Urban
Product
Cpanel::JSON::XS
Classifications
CWE-763, CWE-755, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 3, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 3, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <4.41

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Reini Urban · Cpanel::JSON::XSversion=0 <4.41

Published CVSS scores

7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-763Release of Invalid Pointer or Reference
CWE-755Improper Handling of Exceptional Conditions
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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