CVE-2026-42756Network attack vector

Authenticated arbitrary file deletion via traversal

Published May 27, 2026 · Updated May 27, 2026

Path traversal in Webdeclic QuickWebP 3.2.7 and earlier allows remote authenticated users to delete arbitrary server files via AJAX. The undo-optimization AJAX action accepts an attachment-associated path and deletes it without restricting the target to an expected generated WebP file inside the uploads directory. Contributor-level access is required, and deletion can remove site or server files accessible to PHP, interrupting the WordPress site.

CVSS severity9.9
Critical
EPSS probability0.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Path traversal in Webdeclic QuickWebP 3.2.7 and earlier allows remote authenticated users to delete arbitrary server files via AJAX. The undo-optimization AJAX action accepts an attachment-associated path and deletes it without restricting the target to an expected generated WebP file inside the uploads directory. Contributor-level access is required, and deletion can remove site or server files accessible to PHP, interrupting the WordPress site.

The record

CVE
CVE-2026-42756
Published
May 27, 2026
Updated
May 27, 2026
Vendor
Ludwig You
Product
QuickWebP
Classifications
CWE-22, CAPEC-126, T1070.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 27, 2026CVE publishedPublication date reported by the CVE source.
  2. May 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=0 <=3.2.7 changes=[{"at":"3.2.8","status":"unaffected"}]

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Ludwig You · QuickWebPversion=0 <=3.2.7 changes=[{"at":"3.2.8","status":"unaffected"}]

Published CVSS scores

9.9PatchstackCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CAPEC-126Path Traversal
T1070.004File Deletion

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo