CVE-2026-48901Network attack vectorHinoki check available

Input-filter bypass via omitted Unicode cache flag

Published May 26, 2026 · Updated May 26, 2026

Input-filter bypass in Joomla! CMS 4.0.0 through 5.4.5 and 6.0.0 through 6.1.0 allows remote attackers to retain supplementary Unicode characters. InputFilter::getInstance() hashes five constructor arguments for its instance cache key but omits the stripUSC flag, so calls requesting different supplementary-Unicode policies can receive the same cached filter. Exploitation requires an application path that creates colliding filter instances; the bounded consequence is processing input under the wrong Unicode-stripping policy.

CVSS severity7.5
High
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Input-filter bypass in Joomla! CMS 4.0.0 through 5.4.5 and 6.0.0 through 6.1.0 allows remote attackers to retain supplementary Unicode characters. InputFilter::getInstance() hashes five constructor arguments for its instance cache key but omits the stripUSC flag, so calls requesting different supplementary-Unicode policies can receive the same cached filter. Exploitation requires an application path that creates colliding filter instances; the bounded consequence is processing input under the wrong Unicode-stripping policy.

The record

CVE
CVE-2026-48901
Published
May 26, 2026
Updated
May 26, 2026
Vendor
Joomla! Project
Product
Joomla! CMS
Classifications
CWE-524, CAPEC-204
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 26, 2026CVE publishedPublication date reported by the CVE source.
  2. May 26, 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=4.0.0-5.4.5
  2. Affected versionversion=6.0.0-6.1.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Joomla! Project · Joomla! CMSversion=4.0.0-5.4.5; version=6.0.0-6.1.0

Published CVSS scores

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

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-524Use of Cache Containing Sensitive Information
CAPEC-204Lifting Sensitive Data Embedded in Cache

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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