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Zip-Slip in the Nx self-hosted remote cache

High
FrozenPandaz published GHSA-vp3h-ghgh-jr7g Jul 10, 2026

Package

npm @nx/azure-cache (npm)

Affected versions

*

Patched versions

N/a
npm @nx/gcs-cache (npm)
*
N/a
npm @nx/powerpack-azure-cache (npm)
*
N/a
npm @nx/powerpack-gcs-cache (npm)
*
N/a
npm @nx/powerpack-s3-cache (npm)
*
N/a
npm @nx/powerpack-shared-fs-cache (npm)
*
N/a
npm @nx/s3-cache (npm)
*
N/a
npm @nx/shared-fs-cache (npm)
*
N/a
npm nx (npm)
>= 20.8.0 <= 22.7.6, 23.0.0, 23.0.1
> 23.0.2, 22.7.7

Description

Summary

The Nx self-hosted HTTP remote cache extracts downloaded cache artifacts without constraining where files are written. A malicious — or on-path (MITM) — remote cache server can return a crafted tar archive whose entries escape the cache directory and write to arbitrary locations on the machine running Nx. This arbitrary file write can be escalated to remote code execution. The directly exploitable issue is the self-hosted HTTP remote cache.

Severity

High — CVSS v4.0 8.7 (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N)

Affected Packages

Important

Nx's default local cache and Nx Cloud are NOT affected. The default local cache and Nx Cloud use separate cache retrieval and extraction mechanisms that does not have this vulnerability. Only workspaces that use a self-hosted remote cache (NX_SELF_HOSTED_REMOTE_CACHE_SERVER, @nx/s3-cache, etc.) are affected.

Two self-hosted cache surfaces are affected:

  1. The built-in HTTP remote cache (NX_SELF_HOSTED_REMOTE_CACHE_SERVER, in nx) — fixed in the patched release.
  2. The self-hosted cache packages — @nx/s3-cache, @nx/gcs-cache, @nx/azure-cache, @nx/shared-fs-cache (and their @nx/powerpack-* predecessors) — the same flaw in their own extractor. Deprecated (CVE-2025-36852) and not patched; migrate off (see Remediation).

The shared step that copies cached outputs into the workspace was also part of the exposure and is hardened in the patched nx release.

Remediation

Upgrade to Nx 22.7.7 or 23.0.2 (or later). The patched extractor is a drop-in — no configuration change is required.

If you use the S3, GCS, Azure, or shared-filesystem cache packages

@nx/s3-cache, @nx/gcs-cache, @nx/azure-cache, and @nx/shared-fs-cache (and their @nx/powerpack-* predecessors) are separately versioned packages and are already deprecated (see CVE-2025-36852). Upgrading nx hardens the shared restore step, but it does not fully secure these packages. The remediation for them is to migrate off — to Nx Cloud or the self-hosted OpenAPI/HTTP remote cache — per the deprecation guidance: https://nx.dev/docs/reference/deprecated/self-hosted-cache-packages

Details

When Nx retrieves an artifact from the self-hosted HTTP remote cache, it downloads a gzipped tar archive and extracts it. The extractor joined each untrusted tar entry name directly onto the output directory and unpacked it with tar's unguarded Entry::unpack(), which performs no containment check:

// vulnerable
let path_on_disk = output_dir.join(entry_path); // entry_path is attacker-controlled
fs::create_dir_all(path_on_disk.parent()…)?;
entry.unpack(&path_on_disk)?;

In addition, restore now copies only the declared task outputs (never the whole cache directory), confined to the workspace root; parent directories are realized as real directories so a write can never traverse a symlink; declared outputs that resolve outside the workspace are rejected; and the malformed-input cases return errors instead of panicking.

References

  • Fix: #36116 (merged)
  • TLS-verification warning follow-up: #36132 (merged)
  • Vulnerable extractor introduced in Nx 20.8.0: #30593

Credits

  • Lidor B., Novee Security — Reporter
  • Assaf Levkovich, Novee Security — Reporter

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v4 base metrics

Exploitability Metrics
Attack Vector Network
Attack Complexity Low
Attack Requirements None
Privileges Required None
User interaction Passive
Vulnerable System Impact Metrics
Confidentiality High
Integrity High
Availability High
Subsequent System Impact Metrics
Confidentiality None
Integrity None
Availability None

CVSS v4 base metrics

Exploitability Metrics
Attack Vector: This metric reflects the context by which vulnerability exploitation is possible. This metric value (and consequently the resulting severity) will be larger the more remote (logically, and physically) an attacker can be in order to exploit the vulnerable system. The assumption is that the number of potential attackers for a vulnerability that could be exploited from across a network is larger than the number of potential attackers that could exploit a vulnerability requiring physical access to a device, and therefore warrants a greater severity.
Attack Complexity: This metric captures measurable actions that must be taken by the attacker to actively evade or circumvent existing built-in security-enhancing conditions in order to obtain a working exploit. These are conditions whose primary purpose is to increase security and/or increase exploit engineering complexity. A vulnerability exploitable without a target-specific variable has a lower complexity than a vulnerability that would require non-trivial customization. This metric is meant to capture security mechanisms utilized by the vulnerable system.
Attack Requirements: This metric captures the prerequisite deployment and execution conditions or variables of the vulnerable system that enable the attack. These differ from security-enhancing techniques/technologies (ref Attack Complexity) as the primary purpose of these conditions is not to explicitly mitigate attacks, but rather, emerge naturally as a consequence of the deployment and execution of the vulnerable system.
Privileges Required: This metric describes the level of privileges an attacker must possess prior to successfully exploiting the vulnerability. The method by which the attacker obtains privileged credentials prior to the attack (e.g., free trial accounts), is outside the scope of this metric. Generally, self-service provisioned accounts do not constitute a privilege requirement if the attacker can grant themselves privileges as part of the attack.
User interaction: This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable system. This metric determines whether the vulnerability can be exploited solely at the will of the attacker, or whether a separate user (or user-initiated process) must participate in some manner.
Vulnerable System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the VULNERABLE SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the VULNERABLE SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the VULNERABLE SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
Subsequent System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the SUBSEQUENT SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the SUBSEQUENT SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the SUBSEQUENT SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVE ID

CVE-2026-71476

Weaknesses

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. Learn more on MITRE.

Improper Link Resolution Before File Access ('Link Following')

The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource. Learn more on MITRE.