CVE-2026-58075

Executive Summary

CVE-2026-58075 is an unauthenticated arbitrary file read vulnerability in the HackerOne platform (vendor/component designation currently indeterminate), enabling a remote attacker to read sensitive files from the underlying host system. The flaw is further exploitable to achieve local privilege escalation following the initial file disclosure. With a CVSS score currently unassigned (N/A), the vulnerability carries an EPSS score of 0.00281 (20.3% percentile), indicating low immediate exploitation likelihood in the wild. The vulnerability is unpatched as of this intelligence report, with no vendor fix, workaround, or patch evidence from any tracked source.

Technical Analysis

CVE-2026-58075 resides in an unspecified component of the HackerOne platform, exposing a mechanism by which an unauthenticated remote attacker can read arbitrary files from the host filesystem. The underlying weakness is classified under CWE-287 (Improper Authentication), indicating that the vulnerability stems from a failure to properly verify the identity of the requesting party before granting access to file-read functionality.

Vulnerability Mechanism:

The flaw allows unauthenticated file disclosure—likely through a path traversal, symlink follow, or improper input validation within a file-serving endpoint. Common implementations of this vulnerability class involve:

1. Path traversal: An endpoint such as /download?file=report.txt fails to sanitize ../ sequences, allowing GET /download?file=../../../../etc/passwd.
2. Symlink race (TOCTOU): A file access routine processes user-controlled paths and follows symlinks without verifying that the target file resides within an allowed directory.
3. Improper authentication on internal endpoints: A development or administrative endpoint (e.g., /debug/readfile) lacks authentication middleware, permitting direct file reads.

Attack Surface:

• Network exposure: The affected service is internet-facing (HackerOne is a public bug bounty platform), expanding the attack surface to any remote party.
• Pre-auth access: No credentials or session are required to trigger the file-read condition.
• Host-level impact: Successfully reading files such as /etc/shadow, environment configuration files, API keys, TLS private keys, or application secrets can lead directly to lateral movement or privilege escalation on the host.

Privilege Escalation Vector:

The NVD description states the initial file read "can be further leveraged to escalate privileges locally." This implies that files readable via this flaw may include credential stores, scheduled task definitions, SSH keys, or system service configurations that grant the attacker a foothold to execute code with elevated privileges.

Version and Patch Status:

Affected version ranges are unspecified; no OSV packages, patch sources, or vendor fix references exist. Patch confidence is 0/4—unpatched.

Exploitation Scenarios

The following attack chain details a plausible exploitation path for CVE-2026-58075, assuming a vulnerable web-facing HackerOne-hosted endpoint:

Step 1 — Reconnaissance and Target Identification

The attacker performs passive reconnaissance on hackerone.com and its subdomains, mapping endpoints that handle file retrieval or reporting functionality. Using directory brute-forcing tools (e.g., Feroxbuster, ffuf) and inspecting JavaScript bundles for API route references, the attacker discovers an endpoint resembling:

• /api/v1/attachments/download?token=...
• /download?file=
• /files?path=
• /debug/read?file=

Step 2 — Trigger and Weaponization of the File-Read Flaw

The attacker crafts HTTP requests to the identified endpoint, injecting path traversal payloads:

GET /download?file=../../../../../../../etc/passwd HTTP/1.1
Host: targetsite.hackerone.com

If the application returns the contents of /etc/passwd (or an error revealing file existence), the attacker confirms the traversal. Next, they escalate to targeting high-value files:

GET /download?file=../../../../../../proc/self/environ HTTP/1.1
GET /download?file=../../../../../../etc/shadow HTTP/1.1
GET /download?file=../../../../../../root/.ssh/id_rsa HTTP/1.1
GET /download?file=../../../../../../var/lib/mysql/.my.cnf HTTP/1.1

Step 3 — Payload Execution and Credential Harvesting

The attacker obtains sensitive data from the leaked files, including:

• Environment variables containing database credentials and API tokens.
• SSH private keys.
• Application configuration files with secrets.
• Service account credentials (for the local privilege escalation step).

Step 4 — Post-Exploitation and Privilege Escalation

Using the gathered credentials, the attacker authenticates to the host (e.g., via SSH with the leaked private key) with an unprivileged user account. They then leverage locally readable sensitive files (e.g., sudoers misconfiguration, world-readable cron jobs, or a setuid binary associated with the leaked credentials) to escalate to root or a high-privilege service account, achieving full host compromise.

Impact Assessment

Business Impact:

• Confidentiality: Critical—unauthorized reading of arbitrary files exposes proprietary source code, customer data (HackerOne hosts vulnerability reports containing client-sensitive information), internal credentials, and cryptographic keys.
• Integrity: Indirect—disclosed secrets can enable modification of data, code, or system state.
• Availability: Indirect—compromised credentials can be used to shut down or disrupt services.

Affected Systems:

All hosts running the vulnerable HackerOne platform component. Since the exact component and version are unspecified, the attack surface covers the full HackerOne production environment and any self-hosted instances.

Blast Radius:

• The file-read primitive alone enables mass credential theft.
• The local privilege escalation vector grants full host control.
• The confidentiality breach may violate GDPR (customer data) and NDAs for vulnerability reports handled by the platform.
• Downstream supply-chain risk: leaked API keys or signing certificates can be abused to impersonate HackerOne.

CVSS Interpretation:

With no CVSS vector assigned, reference the EPSS score of 0.00281; while exploitation likelihood is currently low, the severity of an unauthenticated arbitrary file read (typically CVSS 7.5–9.8 depending on privilege escalation) warrants priority remediation planning.

Detection Guidance

Sigma Rule

title: HackerOne Arbitrary File Read - Path Traversal Attempt
id: 6f8a1c2e-4d55-4c9a-8f11-9b0d5e2a7c3f
status: experimental
description: Detects path traversal payloads targeting file-read endpoints on HackerOne platform
logsource:
  category: webserver
  product: apache
  definition: 'Web server access logs for HackerOne endpoints'
detection:
  selection_path:
    cs-uri-query|contains:
      - 'file='
      - 'path='
      - 'download='
      - 'read='
    cs-uri-query|contains|all:
      - '../'
      - '..%2f'
      - '%2e%2e'
      - '..\\'
  selection_sensitive:
    cs-uri-query|contains:
      - 'etc/passwd'
      - 'etc/shadow'
      - 'proc/self/environ'
      - '.ssh/id_rsa'
      - '.git/config'
  condition: selection_path and selection_sensitive
  timeframe: 5m
level: high
fields:
  - client_ip
  - cs_host
  - cs_uri_stem
  - cs_uri_query
falsepositives:
  - Legitimate file download features that use relative paths
tags:
  - attack.t1190
  - attack.initial_access

YARA Rule

rule HackerOne_ArbitraryFileRead_Traversal
{
    meta:
        author = "ValterSIT Threat Intel"
        description = "Detects path traversal strings targeting file-read endpoints"
        cve = "CVE-2026-58075"
        date = "2026-02-01"
        severity = "high"
    strings:
        $a1 = "../../../etc/passwd" ascii wide nocase
        $a2 = "..\\..\\..\\etc\\shadow" ascii wide nocase
        $a3 = "..%2f..%2f..%2fproc%2fself%2fenviron" ascii wide nocase
        $a4 = "file=" ascii wide nocase
        $a5 = "download=" ascii wide nocase
        $a6 = "read=" ascii wide nocase
        $b1 = "etc/passwd" ascii wide nocase
        $b2 = "etc/shadow" ascii wide nocase
        $b3 = ".ssh/id_rsa" ascii wide nocase
        $b4 = ".git/config" ascii wide nocase
    condition:
        (any of ($a*) and any of ($b*)) or
        (all of ($a1, $a2, $a3)) or
        (any of ($b*) and 2 of ($a*))
}

Suricata IDS Rule

alert http any any -> any any (msg:"CVE-2026-58075 HackerOne Arbitrary File Read - Path Traversal Attempt"; flow:established,to_server; content:"GET"; http_method; nocase; content:"file="; http_uri; nocase; content:"..%2f"; http_uri; nocase; pcre:"/(?:\.\.(?:\/|%2f)){2,}(?:etc|proc|var|root|usr|home)\//i"; classtype:attempted-admin; sid:202658075; rev:1; metadata:created_at 2026_02_01, updated_at 2026_02_01, cve CVE-2026-58075;)

Elastic Detection

// Elastic EQL - Detect path traversal in file-read endpoints (HackerOne)
sequence by source.ip
  with maxspan=5m
  [ network where event.type == "request" and http.request.method == "GET"
    and url.path in ("/download", "/files", "/read", "/api/v1/attachments") 
    and (url.query contains "file=" or url.query contains "path=" or url.query contains "download=")
    and (url.query contains "../" or url.query contains "..%2f" or url.query contains "%2e%2e") ]
  [ network where event.type == "request"
    and (url.query contains "etc/passwd" or url.query contains "etc/shadow" 
         or url.query contains "proc/self" or url.query contains ".ssh/" 
         or url.query contains ".git/config") ]

Splunk SPL Query

sourcetype="access_combined" 
| spath input=uri_path output=path path=path
| spath input=uri_query output=query query=query
| search (path IN ("/download","/files","/read","/api/v1/attachments") OR query="*file=*" OR query="*path=*" OR query="*download=*")
  AND (query="*../*" OR query="*..%2f*" OR query="*%2e%2e*")
  AND (query="*etc/passwd*" OR query="*etc/shadow*" OR query="*proc/self*" OR query="*.ssh/*" OR query="*.git/config*")
| table _time, clientip, host, uri_path, uri_query, status
| sort - _time

Wazuh OSSEC Rule

<group name="web_application,">
  <rule id="202658" level="12">
    <decoded>path traversal attempt on HackerOne file-read endpoint</decoded>
    <match>file=|path=|download=|read=</match>
    <regex>\.\.(/|%2f|\\).{0,50}(etc/passwd|etc/shadow|proc/self|\.ssh/|\.git/config)</regex>
    <description>CVE-2026-58075: Attempted arbitrary file read via path traversal</description>
    <group>attack.initial_access,attack.t1190,pci_dss_6.5.1,</group>
    <mitre>
      <id>T1190</id>
    </mitre>
    <info type="cve">CVE-2026-58075</info>
    <options>no_full_log</options>
  </rule>
</group>

Mitigation & Patch Guidance

Patch Confidence: 0/4 — UNPATCHED. No patched version exists, no vendor advisory, no workaround formally documented.

1. Immediate Mitigations (until vendor patch):

• Network-level blocking: Deploy WAF rules (ModSecurity/OWASP CRS) to block path traversal patterns (../, ..%2f, %2e%2e) in any URI query parameter containing file=, path=, download=, read=.
• Restrict access: If the vulnerable platform component is not required for public access, restrict the affected endpoints to authorized internal IP ranges via firewall/security group rules.
• Monitoring: Enable real-time alerting on the Sigma/Splunk/Elastic rules above. Investigate any hits immediately.
• Credential rotation: If any exposure is suspected, rotate all host and application credentials, TLS keys, and API secrets.
• Endpoint hardening: Temporarily disable unauthenticated access to file-serving endpoints; require API keys or session authentication as an interim control.

2. Patch/Upgrade Steps:

• Since no patch exists, monitor HackerOne's official security advisories and the CVE assignment source (NVD page for CVE-2026-58075) for updates.
• Subscribe to HackerOne's release notes/changelog for the affected component.
• When a fix is released, apply it immediately in a staging environment first, then production.
• If the product is self-hosted, follow vendor upgrade documentation and re-run regression tests on file-download functionality.

3. Long-Term Hardening:

• Input validation: Implement allowlist-based path validation for all file-serving endpoints; reject any request containing traversal sequences or absolute paths.
• Authentication enforcement: Ensure all file-read endpoints require authentication and authorization checks.
• Filesystem containment: Run the application in a container with a read-only root filesystem and only mount required directories.
• Secrets management: Store credentials in a dedicated vault (e.g., HashiCorp Vault) rather than filesystem config files.
• Least privilege: Ensure the application service account runs with minimal OS privileges to limit the impact of local privilege escalation.
• Security review: Conduct a code audit of all endpoints handling file inputs to identify similar flaws.

References

1. NVD Entry: https://nvd.nist.gov/vuln/detail/CVE-2026-58075 (official vulnerability descriptor, CWE-287 classification)
2. CVE.org Record: https://cve.org/CVERecord?id=CVE-2026-58075 (CVE assignment source)
3. HackerOne Security Advisories: https://hackerone.com/security (monitor for vendor patch/advisory; currently no published fix)
4. FIRST EPSS Data: https://www.first.org/epss/ (CVE-2026-58075 entry, EPSS=0.00281)

Exploit-in-the-Wild Evidence: No active exploitation campaigns or CISA KEV listing exist as of this report. A public PoC is available (per intelligence data), increasing the risk of weaponization; however, no Nuclei template or public exploit code has been observed. Enterprises running HackerOne platform components should treat this as a high-priority unpatched vulnerability and apply the mitigations above.