CVE-2026-19907

Shipo 1.6 - 1.8.0 - Authentication Bypass to Administrator

Published Nov 14, 2026 CVSS 3.1 · 9.8 Critical EPSS n/a KEV · Not listed

Description

The Shipo plugin for WordPress is vulnerable to Authentication Bypass in versions 1.6 through 1.8.0. This is due to the `authenticate_rest_user()` function parsing the `LOGGED_IN_COOKIE` value and authenticating the named user without verifying the cookie's cryptographic signature. The function's intended `/wp-json/shipo/` route restriction can also be bypassed by placing that substring in the query string of an unrelated REST endpoint. This makes it possible for unauthenticated attackers who know an existing username to impersonate that user, including an administrator, and perform authorized actions through the REST API, including creating another administrator account.

Analysis

Technical impact

The Shipo plugin’s authenticate_rest_user() function parses the LOGGED_IN_COOKIE and authenticates the named user without verifying the cryptographic signature, enabling an attacker who knows a valid username to impersonate that user. The plugin’s intended route restriction can also be bypassed by placing the substring "/wp-json/shipo/" in the query string of an unrelated REST endpoint, further facilitating unauthorized access. This allows unauthenticated attackers to impersonate administrators and create new administrator accounts through the REST API.

Affected Systems

WordPress sites using the Shipo plugin versions 1.6 through 1.8.0 are affected.

Risk and Exploitability

With a CVSS score of 9.8 the vulnerability is classified as critical and can be fully exploited by unauthenticated users who know a username. EPSS data is not available, but the lack of mitigations and the clear exploitation path indicate a high probability of exploitation. The vulnerability is not yet listed in the CISA KEV catalog.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

shipo

Shipo

unaffected

Version	Status	Constraints
`1.6`	affected	≤ 1.8.0

No data.

No data available yet.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

Upgrade the Shipo plugin to version 1.8.1 or later, which fixes the authentication bypass.
Implement strict REST API authentication by validating the cookie’s cryptographic signature before allowing any privileged action.
Remove or disable the Shipo plugin if it is not required, and audit the site’s REST endpoints for unexpected backdoor routes.

Generated by OpenCVE AI on November 14, 2026 at 20:23 UTC.

Tracking

Advisories

No advisories available

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

References

Link	Providers
https://plugins.trac.wordpress.org/changeset/3701532/shipo
https://www.wordfence.com/threat-intel/vulnerabilities/id/ce5ea515-5ae1-4771-9bfb-5a0f4b3fce22?source=cve

History

Nov 14, 2026 12:45 PM Description updated. Title updated. Weaknesses updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
Description		The Shipo plugin for WordPress is vulnerable to Authentication Bypass in versions 1.6 through 1.8.0. This is due to the `authenticate_rest_user()` function parsing the `LOGGED_IN_COOKIE` value and authenticating the named user without verifying the cookie's cryptographic signature. The function's intended `/wp-json/shipo/` route restriction can also be bypassed by placing that substring in the query string of an unrelated REST endpoint. This makes it possible for unauthenticated attackers who know an existing username to impersonate that user, including an administrator, and perform authorized actions through the REST API, including creating another administrator account.
Title		Shipo 1.6 - 1.8.0 - Authentication Bypass to Administrator
Weaknesses		CWE-287
References		https://plugins.trac.wordpress.org/changeset/3701532/shipo https://www.wordfence.com/threat-intel/vulnerabilities/id/ce5ea515-5ae1-4771-9bfb-5a0f4b3fce22?source=cve
Metrics		cvssV3_1 `{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}`