CVE-2026-18645Public exploitNetwork attack vector

Authenticated file moves via unchecked oldfile path

Published Aug 3, 2026 · Updated Aug 3, 2026

Path traversal in HTMLy 3.1.0 through 3.1.1 allows remote authenticated users to move server files via the admin content endpoint. The add_content function in /system/admin/admin.php passes the request-controlled oldfile path directly to PHP rename without validating or restricting its location. Any valid session suffices; exploitation can relocate PHP-readable files into web-accessible content and interrupt application operation.

CVSS severityUnavailable
Unscored
EPSS probability0.43%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in HTMLy 3.1.0 through 3.1.1 allows remote authenticated users to move server files via the admin content endpoint. The add_content function in /system/admin/admin.php passes the request-controlled oldfile path directly to PHP rename without validating or restricting its location. Any valid session suffices; exploitation can relocate PHP-readable files into web-accessible content and interrupt application operation.

The record

CVE
CVE-2026-18645
Published
Aug 3, 2026
Updated
Aug 3, 2026
Vendor
Danang Probo Sayekti
Product
HTMLy
Classifications
CWE-22
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 3, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 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=3.1.0
  2. Affected versionversion=3.1.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Danang Probo Sayekti · HTMLyversion=3.1.0; version=3.1.1

Published CVSS scores

5.5VulDB CNAAV:N/AC:L/Au:S/C:N/I:P/A:P/E:POC/RL:ND/RC:UR
5.4VulDB CNACVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L/E:P/RL:X/RC:R
5.4VulDB CNACVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L/E:P/RL:X/RC:R
5.3VulDB CNACVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:P

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.

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Public exploit references

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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