CVE-2026-86241Public exploitNetwork attack vector

Cookie forgery via empty validation key

Published Sep 7, 2026 · Updated Sep 7, 2026

Cookie validation weakness in FeehiCMS 2.1.0 and 2.1.1 allows remote attackers to forge Yii2-managed cookies with an empty key. The production backend and frontend templates assign cookieValidationKey an empty string, while initialization and Docker startup do not generate a secret. Identity-cookie abuse requires nondefault auto-login and the correct Yii2 serialization format; otherwise the exposed key breaks cookie and CSRF-token integrity.

CVSS severityUnavailable
Unscored
EPSS probability0.46%
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

Cookie validation weakness in FeehiCMS 2.1.0 and 2.1.1 allows remote attackers to forge Yii2-managed cookies with an empty key. The production backend and frontend templates assign cookieValidationKey an empty string, while initialization and Docker startup do not generate a secret. Identity-cookie abuse requires nondefault auto-login and the correct Yii2 serialization format; otherwise the exposed key breaks cookie and CSRF-token integrity.

The record

CVE
CVE-2026-86241
Published
Sep 7, 2026
Updated
Sep 7, 2026
Vendor
liufee
Product
FeehiCMS
Classifications
CWE-320, CWE-321, T1606.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 7, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 7, 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=2.1.0
  2. Affected versionversion=2.1.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

liufee · FeehiCMSversion=2.1.0; version=2.1.1

Published CVSS scores

4.3VulDB CNACVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N/E:P/RL:X/RC:R
5.0VulDB CNAAV:N/AC:L/Au:N/C:P/I:N/A:N/E:POC/RL:ND/RC:UR
4.3VulDB CNACVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N/E:P/RL:X/RC:R
5.3VulDB CNACVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:N/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.

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 exploitPublished

Weakness, pattern, technique

CWE-320Key Management Errors
CWE-321Use of Hard-coded Cryptographic Key
T1606.001Forge Web Credentials: Web Cookies

Public exploit references

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