CriticalCVE-2026-47754

unauthenticated path traversal in Metacat 2.x (CVE-2026-47754)

Published 10.08.2026Last modified 23.10.2026Sources: CVE.org, EUVD

What is affected, what to do

Update NCEAS Metacat to version 3.0.0.

Affected: NCEAS Metacat lt *..3.0.0
Fixed in: NCEAS Metacat 3.0.0

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Metrics

9.3

XIEM Effective CVSS

Highest available CVSS rating from NVD and vendor data.

Source: Vendor (CNA), CVSS v3

9.3

CVSS v3

Severity Critical on the scale from 0 to 10.

Source: CVE.org, EUVD

0.5 %

EPSS score

Low — model estimates < 1% exploitation likelihood.

Source: FIRST EPSS, percentile 41.6

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: 81.88 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: 9.3 Methodology
CVSS v3 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: 9.3
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: 0.5 %; 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: 41.6; High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
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: 10.08.2026
CISA assessment (SSVC): Exploitation: none known · automatable · Technical impact: partial; Source: CISA Vulnrichment, as of 10 August 2026
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-22, CWE-862

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

Metacat is data repository software that helps researchers preserve, share, and discover data. Versions 2.x through 2.19.1 and all 1.x versions contain an unauthenticated path traversal in the `archiveEntryName` parameter of the `action=read` endpoint that is part of the original 1.x Metacat API. `ArchiveHandler.readArchiveEntry()` concatenates the user-supplied parameter into a filesystem path without validation, and the surrounding `hasReadPermission()` check is commented out. An unauthenticated remote attacker can read any file accessible to the Tomcat process by sending a single GET request. Proof-of-concept exploits have been demonstrated and verified against this vulnerability, and it should be considered easily exploitable for any Metacat deployment < 3.0.0 by any user with access to the 1.x API. Through this vulnerability, production 2.x deployments are exposed to credential theft, client certificate and private key exfiltration enabling member node impersonation within the federation, embargoed research data disclosure, and broad system reconnaissance. Given Metacat's deployment footprint across the DataONE network of repositories and federally funded research programs, the population of exposed 2.x instances is non-trivial. The vulnerability was eliminated in Metacat version 3.0.0 and after by eliminating the entire Metacat 1.x API that exposed this vulnerability. The vulnerability was remediated in April 2024 with the release of Metacat 3.0.0, which removed the legacy Metacat API including ArchiveHandler.java. The commit message and issue reference architectural cleanup, not a security fix, and no advisory or CVE was issued. The 2.x branch was not and will not be backported, as is standard practice in Metacat, which only supports the most current release. 2.19.1 remains vulnerable with identical code and is beyond its supported lifetime. As a workaround, disable or restrict 1.x API servlets. Because the vulnerable 1.x API is no longer used or necessary in most Metacat deployments, restricting access to the old API endpoints can reduce or eliminate exposure for 2.19.x deployments. After removing those features, restart Tomcat or whichever software is hosting the servlets.

Source: NVD (NIST), ENISA EUVD, cvelistv5

Affected products

The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

Affected products
		Affected versions	Fixed in
NCEAS	metacat	`< 3.0.0`	`3.0.0`

Vendors and products

Nceas Metacat

Weakness classes (CWE)

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Base
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.
Entry at MITRE CWE-22
CWE-862Missing Authorization
Class
The product does not perform an authorization check when an actor attempts to access a resource or perform an action.
Entry at MITRE CWE-862

References & sources

github.comNCEAS/metacat/security/advisories/GHSA-m852-f287-7cgwx_refsource_CONFIRM, euvd
github.comNCEAS/metacat/issues/1365x_refsource_MISC, euvd
github.comNCEAS/metacat/pull/1713x_refsource_MISC, euvd
github.comNCEAS/metacat/commit/07e034b2bbf7029e28af32f472f4d70ea6b5ab1bx_refsource_MISC, euvd

Changes to this CVE

Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

10.08.2026Record modifiedCISA ADP

CISA assessment (SSVC): exploitation: none known, automatable: yes

Show the original change

Individual changes of this event as published by NVD
Type	Action	Before	After
SSVC assessment	added	—	{"id":"CVE-2026-47754","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"partial"}],"version":"2.0.3","timestamp":"2026-08-10T18:10:55.286374Z"}

Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0

10.08.2026ReceivedGitHub

CVSS V3.1: AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N

Weakness type: CWE-22, CWE-862

Description added or changed

New references:

Show 9 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
Affected versions (publisher)	added	—	metacat
Description	added	—	Metacat is data repository software that helps researchers preserve, share, and discover data. Versions 2.x through 2.19.1 and all 1.x versions contain an unauthenticated path traversal in the `archiveEntryName` parameter of the `action=read` endpoint that is part of the original 1.x Metacat API. `ArchiveHandler.readArchiveEntry()` concatenates the user-supplied parameter into a filesystem path without validation, and the surrounding `hasReadPermission()` check is commented out. An unauthenticated remote attacker can read any file accessible to the Tomcat process by sending a single GET request. Proof-of-concept exploits have been demonstrated and verified against this vulnerability, and it should be considered easily exploitable for any Metacat deployment < 3.0.0 by any user with access to the 1.x API. Through this vulnerability, production 2.x deployments are exposed to credential theft, client certificate and private key exfiltration enabling member node impersonation within the federation, embargoed research data disclosure, and broad system reconnaissance. Given Metacat's deployment footprint across the DataONE network of repositories and federally funded research programs, the population of exposed 2.x instances is non-trivial. The vulnerability was eliminated in Metacat version 3.0.0 and after by eliminating the entire Metacat 1.x API that exposed this vulnerability. The vulnerability was remediated in April 2024 with the release of Metacat 3.0.0, which removed the legacy Metacat API including ArchiveHandler.java. The commit message and issue reference architectural cleanup, not a security fix, and no advisory or CVE was issued. The 2.x branch was not and will not be backported, as is standard practice in Metacat, which only supports the most current release. 2.19.1 remains vulnerable with identical code and is beyond its supported lifetime. As a workaround, disable or restrict 1.x API servlets. Because the vulnerable 1.x API is no longer used or necessary in most Metacat deployments, restricting access to the old API endpoints can reduce or eliminate exposure for 2.19.x deployments. After removing those features, restart Tomcat or whichever software is hosting the servlets.
CVSS	added	—	AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N
Weakness type (CWE)	added	—	CWE-22
Weakness type (CWE)	added	—	CWE-862
Reference	added	—	https://github.com/NCEAS/metacat/commit/07e034b2bbf7029e28af32f472f4d70ea6b5ab1b
Reference	added	—	https://github.com/NCEAS/metacat/issues/1365
Reference	added	—	https://github.com/NCEAS/metacat/pull/1713
Reference	added	—	https://github.com/NCEAS/metacat/security/advisories/GHSA-m852-f287-7cgw

Source identifier: security-advisories@github.com

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