CVE-2026-12568: Path Traversal in postman_download Module

Technical summary

The postman_download module processes workspace metadata from the Postman API and uses the workspace name field directly in pathlib path construction without sanitization or validation. The vulnerability is classified as CWE-22 (Improper Limitation of a Pathname to a Restricted Directory / Path Traversal). When pathlib resolves a path containing traversal sequences, it can escape the intended output directory. An unauthenticated remote attacker can create or modify a workspace on Postman with a malicious name containing path traversal characters. When a user downloads that workspace using the affected module, the traversal payload is interpreted by pathlib, resulting in arbitrary file write capabilities with the privileges of the user running the download operation. No authentication is required on the attacker side to create the malicious workspace, and user interaction (initiating the download) is the only prerequisite.

Business impact

This vulnerability poses a moderate but real risk to users and organizations relying on postman_download for API development workflows. An attacker can plant malicious files on developer machines, potentially leading to code injection in projects, supply chain compromise if developers commit poisoned files, or execution of arbitrary scripts if files are written to startup directories. The impact is limited to the individual user's system rather than the Postman service itself, but the ease of exploitation and low barrier to attack creation make this a concern for teams managing developer security. Organizations should assess whether postman_download is used in CI/CD pipelines or shared development environments, where the blast radius could be larger.

Affected systems

The postman_download module is affected. No specific version bounds are provided in the source data; verify against the vendor advisory for affected and patched versions. Any system running postman_download and downloading workspaces from Postman API is potentially at risk. The attack surface includes developers, API testers, and automation systems that regularly synchronize Postman workspaces locally.

Exploitability

Exploitability is straightforward. An attacker needs only to create a Postman workspace (or compromise an existing one) and rename it with path traversal sequences such as ../../../tmp/malicious_file or similar patterns. When any user downloads that workspace, the traversal is triggered. No special technical skills are required on the attacker side; the attack is entirely dependent on user action (downloading the workspace). The CVSS vector reflects this: network-based, low attack complexity, no privileges required, but user interaction needed. The vulnerability has not been added to CISA's Known Exploited Vulnerabilities catalog as of the modification date.

Remediation

Apply vendor patches immediately upon availability. Until patches are deployed, users should avoid downloading workspaces from untrusted sources and validate workspace names in the Postman UI before initiating downloads. Organizations should consider restricting postman_download usage in shared or high-security environments pending patch deployment. Code review and static analysis should be performed on any postman_download integration to identify hardcoded or dynamic use of downloaded content.

Patch guidance

Monitor the postman_download project repository and Postman security advisories for patch releases. When available, upgrade to the patched version that includes input sanitization and path validation. Test patches in a non-production environment first to ensure compatibility with your download workflows. If using postman_download in CI/CD, update container images and dependency locks accordingly. Verify that the patch properly sanitizes workspace names and restricts path construction to the intended output directory.

Detection guidance

Monitor file system activity for unexpected file creation outside intended postman_download directories, particularly in sensitive locations (/tmp, /home, /root, Windows system directories, or startup folders). Review postman_download process logs and API calls for unusual workspace names containing ../, ..\ or other traversal sequences. If using endpoint detection and response tools, create rules alerting on postman_download writing files outside its configured output path. Inspect downloaded workspace directories for unexpected files, especially executable or script files. Check Postman API audit logs (if available) for workspace rename events by external or suspicious accounts.

Why prioritize this

Although rated MEDIUM severity, this vulnerability merits timely attention because it combines ease of exploitation, low attacker barrier to entry, and direct impact to developer machines. Developer endpoints are often entry points for supply chain attacks. Prioritize patching in organizations where postman_download is used in CI/CD, shared development environments, or by multiple team members. In low-risk scenarios (isolated developer use, trusted workspace sources), this may be lower priority, but should not be deferred indefinitely.

Risk score, explained

The CVSS 3.1 score of 6.5 (MEDIUM) reflects a network-based attack with low complexity and no authentication required, but requiring user interaction. The impact is high for integrity (arbitrary file write) but the scope is unchanged and there is no confidentiality or availability impact from the vulnerability itself. The score appropriately balances the ease of exploitation against the localized blast radius. However, context matters: in a supply chain scenario or CI/CD pipeline, the business impact could exceed the base CVSS score.

Frequently asked questions