CVE-2026-0312

Executive Summary

CVE-2026-0312 is a path traversal vulnerability (CWE-22) in Palo Alto Networks Checkov, distributed by Prisma Cloud, that allows an unauthenticated local user to write files to arbitrary locations on the scanning filesystem. The flaw affects installations where Checkov is executed with write access to a shared or host-mounted filesystem, and the primary impact is integrity loss: an attacker with local execution context can plant or overwrite files outside the intended scan directory, potentially leading to code execution under the context of the scanning process or adjacent processes. No public proof-of-concept, Nuclei template, or exploit code is currently available, and the vulnerability remains unpatched per all tracked sources.

Technical Analysis

The vulnerability class is directory traversal (CWE-22), arising in Palo Alto Networks Checkov as delivered through Prisma Cloud. Per the NVD description, the flaw enables an unauthenticated local user to write files to arbitrary locations on the scanning filesystem. The essential mechanism of CWE-22 write-class traversal is that a file-system path supplied to the application is not normalized and validated against a permitted base directory before being used in a write operation. Sequences such as ../ (and on some platforms encoded or alternate representations) escape the intended working directory and permit file creation or overwrite anywhere the resolving process has permission.

Two characteristics of this CVE materially shape its attack surface:

1. Unauthenticated — the attacker does not need credentials to the Checkov component or Prisma Cloud tenant. The only prerequisite is the ability to execute in, or supply input to, the local context in which Checkov runs.
2. Local user — this is not a remotely reachable, network-facing vulnerability in the classic sense. It requires local access to the scan host or the ability to influence the filesystem/inputs consumed by a Checkov scan.

The description does not disclose the specific parameter, configuration key, rule input, or file-output option that contains the traversal. Accordingly, no specific function, class, API endpoint, file path, or parameter name can be asserted as vulnerable. What can be stated at the vulnerability-class level is that an input controlling a write destination is insufficiently canonicalized before the write is performed. Typical trigger surfaces for this class in an IaC/configuration scanner like Checkov include externally influenced output paths (for example, report or artifact destination arguments), policy/check inputs, or plan/state file references that are parsed and written back. The precise surface here is not specified in available data and should be determined by vendor advisory or source review once published.

Because the impact primitive is arbitrary file write rather than arbitrary read or code execution directly, the direct effect is integrity compromise of the filesystem. Escalation to code execution depends on what files the process can reach — for instance, overwriting a script or configuration consumed by a scheduled job running as a higher-privileged account — but this escalation path is an inference from the impact class and is not documented in the CVE.

Exploitation Scenarios

No public PoC is available; the attack chain below is inferred from the vulnerability class (unauthenticated local arbitrary file write via path traversal) and the NVD description. No specific function names, endpoints, file paths, or parameters from the product are asserted, because none are provided in the available data.

1. Reconnaissance / target identification. An attacker who already holds a low-privileged local account on a host where Checkov runs (for example, a CI runner, build agent, developer workstation, or a container running with a mounted host path) enumerates filesystem layout, scan workspaces, and process context. They identify locations writable by the Checkov process and, importantly, any files later consumed by that process or by a higher-privileged process.

2. Triggering the flaw class. The attacker supplies a crafted path value into the input that Checkov uses to determine a write destination. Because the path is not constrained to a permitted base directory, traversal sequences (e.g., ../) cause the write to resolve outside the intended directory. No authentication is required for this step, consistent with the "unauthenticated local user" characterization.

3. Payload / execution method. At the vulnerability-class level, the payload is a file-write operation with attacker-chosen destination and content. The attacker overwrites or plants a file at the traversed location. The description does not specify content restrictions or file-type limits; the primitive is "write files to arbitrary locations on the scanning filesystem."

4. Post-exploitation impact. Successful exploitation yields integrity loss on the host filesystem. Depending on permission scope and file reachability, an attacker may overwrite files that are subsequently loaded or executed, potentially achieving execution in the context of the Checkov process or an adjacent/higher-privileged consumer of those files. Where no such consumer is reachable, the impact is limited to arbitrary file overwrite/planting (data integrity and potential denial of service via corruption of scanner or system files). This escalation potential is a class-level inference, not a documented outcome of this specific CVE.

Impact Assessment

• Confidentiality: No direct read primitive is described — the stated impact is file write. Confidentiality is not directly implicated (CVSS C:N in the derived vector).
• Integrity: High — the core capability is arbitrary file write to attacker-chosen locations, enabling tampering with scanner outputs, configuration, or other reachable files (CVSS I:H).
• Availability: Not directly stated; availability impact is conditional on whether overwritten files are critical to the scanner or host operation (modeled as A:N absent evidence of guaranteed disruption).
• Attack Vector / Privileges / User Interaction: Local (AV:L), no privileges required (PR:N), no user interaction (UI:N) — reflecting the "unauthenticated local user" description.
• Blast radius: Scoped to the filesystem reachable by the Checkov process. In containerized CI/CD pipelines this may extend to any mounted volumes, shared workspace directories, or host paths exposed to the scan container, which is where an arbitrary-write primitive becomes materially dangerous (tampering with build outputs, cached tooling, or subsequent pipeline stages).
• Exploitability: EPSS is 0.00141 (3.1st percentile), indicating very low near-term exploitation likelihood as of this writing. No CISA KEV listing, no public PoC, and no Nuclei template.

Note: CVSS score/vector were not provided by the source data (N/A). The vector shown in METADATA is an analyst-derived estimate from the CWE and description and should be treated as provisional.

Detection Guidance

Sigma Rule

title: Potential Path Traversal File Write via Checkov (CVE-2026-0312)
id: 9f3c1a70-6b2e-4f5a-9d1c-7a0e2c4b8d31
status: experimental
description: Detects Checkov process activity consistent with path traversal file writes outside expected scan/output directories.
references:
  - https://nvd.nist.gov/vuln/detail/CVE-2026-0312
author: valtersit.com
date: 2026/01/01
logsource:
  category: process_creation
  product: linux
detection:
  selection_img:
    Image|endswith:
      - '/checkov'
      - '/python3'
  selection_cmd_traversal:
    CommandLine|contains:
      - '../'
      - '..%2f'
      - '..%2F'
      - '/etc/'
      - '/root/'
      - '/home/'
  condition: selection_img and selection_cmd_traversal
falsepositives:
  - Legitimate scans referencing parent directories
level: medium

YARA Rule

rule CVE_2026_0312_Checkov_Traversal_Indicators
{
    meta:
        description = "Detects path traversal sequences in Checkov-related artifacts indicating CVE-2026-0312 exploitation attempts"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-0312"
        author = "valtersit.com"
        date = "2026-01-01"
        severity = "medium"

    strings:
        $traversal1 = "../" ascii wide
        $traversal2 = "..%2f" ascii wide nocase
        $checkov = "checkov" ascii wide nocase
        $output = "output_file_path" ascii wide nocase

    condition:
        filesize < 5MB and
        $checkov and
        any of ($traversal*)
}

Suricata IDS Rule

alert http any any -> any any (msg:"CVE-2026-0312 Checkov Path Traversal Attempt"; flow:to_server,established; http.uri; content:"..%2f"; nocase; http.uri; content:"..%2F"; nocase; reference:cve,2026-0312; reference:url,nvd.nist.gov/vuln/detail/CVE-2026-0312; classtype:attempted-admin; sid:20260312; rev:1;)

Note: This CVE is primarily a local filesystem issue. The Suricata rule covers the network-observable subset — traversal payloads delivered over HTTP to a Checkov/Prisma Cloud service endpoint, if any such remote input surface exists. No specific endpoint is confirmed in the data; deploy in detection-only mode.

Elastic Detection

process where process.name in ("checkov", "python3", "python") and
process.command_line regex~ ".*(\.\./|\.\.%2[fF]|\.\.\\\\).*" and
process.parent.name in ("bash", "sh", "runner", "buildkite-agent", "dockerd")

Splunk SPL Query

index=edr OR index=sysmon source=*process*
(Image="*checkov*" OR Image="*python*")
(CommandLine="*../*" OR CommandLine="*..%2f*" OR CommandLine="*..\\*" OR CommandLine="*output_file_path*")
| stats count min(_time) as firstTime max(_time) as lastTime values(CommandLine) as cmds by host user Image
| where count > 0
| convert ctime(firstTime) ctime(lastTime)

Wazuh OSSEC Rule

<group name="palo_alto,prisma,checkov,">
  <rule id="100612" level="10">
    <if_sid>5920</if_sid>
    <field name="command">checkov</field>
    <match>\.\./|\.\.%2f|\.\.\\</match>
    <description>CVE-2026-0312: Possible Checkov path traversal file write attempt detected</description>
    <mitre>
      <id>T1190</id>
    </mitre>
    <group>cve_2026_0312,arbitrary_file_write,</group>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence: 0/4 (UNPATCHED — no patch evidence from any tracked source).

1. Immediate mitigations

   • Run Checkov as a dedicated, low-privileged user inside a container or sandbox with a read-mostly root filesystem and no access to sensitive host paths. Mount only the scan target and a single constrained output directory.
   • Remove or restrict write permissions to locations outside the intended scan/output directory for the account executing Checkov.
   • Treat all path-controlling inputs to Checkov as untrusted; do not pass attacker-influenced destination paths.
   • Enable command-line and filesystem-integrity monitoring (FIM) on hosts and runners where Checkov executes (see Detection Guidance) to catch traversal writes.

2. Patch / upgrade steps

   • No vendor fix or fixed version is identified in any tracked source as of this report. Monitor the Palo Alto Networks security advisories and the Checkov repository for a patched release.
   • When a fix is published, upgrade Checkov/Prisma Cloud components to the fixed version and revalidate the boundary between scan inputs and filesystem write destinations.

3. Long-term hardening

   • Enforce least privilege for all CI/CD scanner processes; isolate build runners from persistent and host-mounted filesystems.
   • Apply path canonicalization and base-directory allowlisting as a defense-in-depth control wherever scanner tools accept filesystem paths.
   • Adopt immutable/disposable runners so any files planted by a tampered scan are discarded between jobs.
   • Integrate SBOM-driven vulnerability tracking so that patched versions are adopted promptly once released.

References

• NVD — CVE-2026-0312: https://nvd.nist.gov/vuln/detail/CVE-2026-0312
• MITRE CWE-22 — Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'): https://cwe.mitre.org/data/definitions/22.html
• Palo Alto Networks Security Advisories: https://security.paloaltonetworks.com/
• Checkov (Prisma Cloud) project: https://github.com/bridgecrewio/checkov
• CISA Known Exploited Vulnerabilities Catalog (CVE-2026-0312 not listed as of this report): https://www.cisa.gov/known-exploited-vulnerabilities-catalog

Exploit-in-the-wild evidence: None identified. No CISA KEV listing, no public PoC, no Nuclei template, and no known threat actor campaign associated with CVE-2026-0312 at the time of writing. EPSS 0.00141 (3.1st percentile) indicates low predicted exploitation likelihood.