Build Cache Poisoning via Untrusted Pull Requests (CVE-2025-36852)
Published Sources: CVE.org, OSV
What is affected, what to do
A critical security vulnerability exists in remote cache extensions for common build systems utilizing bucket-based remote cache (such as those using Amazon S3, Google Cloud Storage, or similar object storage) that allows any contributor with pull request privileges to inject compromised artifacts from an untrusted environment into trusted production environments without detection. The vulnerability exploits a fundamental design flaw in the "first-to-cache wins" principle, where artifacts built in untrusted environments (feature branches, pull requests) can poison the cache used by trusted environments (protected branches, production deployments).
The available sources name no fixed version. Check the vendor guidance in the references below.
- Affected
- Niklas Portmann Azure Based Remote Cache Plugin for Nx
eq 0..0 - Niklas Portmann Minio Based Remote Cache Plugin for Nx
eq 0..0 - Niklas Portmann Nx Remote Cache Utilities
eq 0..0 - Nx AWS S3 Remote Cache Plugin for Nx
eq 0..0 - Nx GCS Remote Cache Plugin for Nx
eq 0..0 - Nx Azure Blob Remote Cache Plugin for Nx
eq 0..0 - Nx Shared File System Cache Plugin for Nx
eq 0..0
- Niklas Portmann Azure Based Remote Cache Plugin for Nx
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Metrics
9.4
Priority
XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.
Source: NVD, CVSS v4
9.4
CVSS v4
Severity Critical on the scale from 0 to 10.
Source: CVE.org, OSV
0.3 %
EPSS score
Low — model estimates < 1% exploitation likelihood.
Source: FIRST EPSS, percentile 16.3
Show all metrics
- Severity
- Critical
Priority (0–325)
The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?
Read in glossary- 58.46 Methodology
Exploit maturity
An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.
Read in glossary- no public PoC known
XIEM Effective CVSS
XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.
Read in glossary- 9.4 Methodology
CVSS v4
CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.
Read in glossary- 9.4
EPSS score
The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.
Read in glossary- 0.3 %
- Low — model estimates < 1% exploitation likelihood.
EPSS percentile
The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.
Read in glossary- 16.3
- Elevated — this CVE ranks above at least 10% of all CVEs scored today.
KEV status
The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.
Read in glossary- —
- Published
- CISA assessment (SSVC)
- Exploitation: none known · not automatable · Technical impact: total
- Source: CISA Vulnrichment, as of 10 June 2025
CWE
CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.
Read in glossary- CWE-829
Detection rules
No NEOSEC detection rule is available for this vulnerability yet.
Classification under NIS2 and CRA
Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.
NIS2
NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.
Read in glossary- High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
CRA
The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.
Read in glossary- From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
ISO/IEC 27001
ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.
Read in glossary- Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.
Description
A critical security vulnerability exists in remote cache extensions for common build systems utilizing bucket-based remote cache (such as those using Amazon S3, Google Cloud Storage, or similar object storage) that allows any contributor with pull request privileges to inject compromised artifacts from an untrusted environment into trusted production environments without detection. The vulnerability exploits a fundamental design flaw in the "first-to-cache wins" principle, where artifacts built in untrusted environments (feature branches, pull requests) can poison the cache used by trusted environments (protected branches, production deployments). This attack bypasses all traditional security measures including encryption, access controls, and checksum validation because the poisoning occurs during the artifact construction phase, before any security measures are applied.
Source: NVD (NIST), OSV (Open Source Vulnerabilities), cvelistv5, CVE.org (MITRE)
Affected products
The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.
| Affected versions | Fixed in | ||
|---|---|---|---|
| Niklas Portmann | Azure Based Remote Cache Plugin for Nx |
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| Niklas Portmann | Minio Based Remote Cache Plugin for Nx |
|
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| Niklas Portmann | Nx Remote Cache Utilities |
|
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| Nx | AWS S3 Remote Cache Plugin for Nx |
|
|
| Nx | Azure Blob Remote Cache Plugin for Nx |
|
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| Nx | GCS Remote Cache Plugin for Nx |
|
|
| Nx | Shared File System Cache Plugin for Nx |
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| npm | @nx/azure-cache |
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|
Vendors and products
Weakness classes (CWE)
CWE-829Inclusion of Functionality from Untrusted Control Sphere
Base
The product imports, requires, or includes executable functionality (such as a library) from a source that is outside of the intended control sphere.
Entry at MITRE CWE-829
References & sources
- NVD (NIST)vuln/detail/CVE-2025-36852advisory
- github.comnrwl/nxpackage
- nx.appfiles/cve-2025-06web
- nx.devblog/creep-vulnerability-build-cache-securityweb
- nx.devdocs/reference/remote-cache-plugins/azure-cache/overviewweb
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<a href="https://intel.neosec.eu/en/cve/CVE-2025-36852"><img src="https://intel.neosec.eu/badge/cve/CVE-2025-36852.svg?lang=en" alt="CVE-2025-36852 – NEOSEC Intel" height="20"></a>