Not ratedCVE-2026-100397

Rucio: Unauthenticated administrator impersonation through SSH challenge tokens (CVE-2026-100397)

Published 13.11.2026Sources: OSV, Hersteller

What is affected, what to do

Update Rucio to version 41.1.1, Rucio to version 40.4.2, Rucio to version 38.6.1.

Affected: Rucio 1.19.7..*
Rucio 1.22.8..*
Rucio 1.25.5..*
Rucio 1.25.6..*
Rucio 1.25.7..*
Rucio 1.26.0..*
Rucio 1.26.0rc1..*
Rucio 1.26.0rc2..*
Rucio 1.26.1..*
Rucio 1.29.3..*
Rucio 37.5.0..*
Rucio 37.6.0..*
Rucio 37.7.0..*
Rucio 37.7.1..*
Rucio 38.0.0..*
Rucio 38.0.0rc1..*
Rucio 38.0.0rc2..*
Rucio 38.0.0rc3..*
Rucio 38.1.0..*
Rucio 38.2.0..*
Rucio 38.3.0..*
Rucio 38.4.0..*
Rucio 38.5.0..*
Rucio 38.5.1..*
Rucio 38.5.2..*
Rucio 38.5.3..*
Rucio 38.5.4..*
Rucio 38.5.5..*
Rucio 38.6.0..*
Rucio *..>= 41.0.0rc1, < 41.1.1
Rucio *..>= 39.0.0rc1, < 40.4.2
Rucio *..>= 36.0.0rc1, < 38.6.1
Rucio *..>= 1.14.0.post1, < 35.9.1
Rucio 1.14.0.post1..*
Rucio 1.14.0.post2..*
Rucio 1.14.1.post1..*
Rucio 1.14.2..*
Rucio 1.14.6..*
Rucio 1.14.7..*
Rucio 1.14.8..*
Rucio 1.14.8.post1..*
Rucio 1.14.8.post2..*
Rucio 1.14.9..*
Rucio 1.14.9.post1..*
Rucio 1.15.0..*
Rucio 1.15.0.post1..*
Rucio 1.15.2..*
Rucio 1.15.3..*
Rucio 1.15.3.post1..*
Rucio 1.15.4..*
Rucio 1.15.4.post1..*
Rucio 1.16.0..*
Rucio 1.16.0.post1..*
Rucio 1.16.1..*
Rucio 1.16.2..*
Rucio 1.16.3..*
Rucio 1.17.0..*
Rucio 1.17.1..*
Rucio 1.17.2..*
Rucio 1.17.2.post1..*
Rucio 1.17.5..*
Rucio 1.17.6..*
Rucio 1.17.6.post1..*
Rucio 1.17.6.post2..*
Rucio 1.17.7..*
Rucio 1.17.8..*
Rucio 1.17.8.post1..*
Rucio 1.17.8.post2..*
Rucio 1.18.0..*
Rucio 1.18.1..*
Rucio 1.18.3..*
Rucio 1.18.4..*
Rucio 1.18.5..*
Rucio 1.18.5.post1..*
Rucio 1.18.6..*
Rucio 1.18.6.post1..*
Rucio 1.18.7..*
Rucio 1.18.8..*
Rucio 1.18.8.post1..*
Rucio 1.18.9..*
Rucio 1.19.0.post2..*
Rucio 1.19.1..*
Rucio 1.19.3..*
Rucio 1.19.4..*
Rucio 1.19.4.post1..*
Rucio 1.19.4.post2..*
Rucio 1.19.5..*
Rucio 1.19.6..*
Rucio 1.19.7.post1..*
Rucio 1.19.8..*
Rucio 1.20.0..*
Rucio 1.20.0rc1..*
Rucio 1.20.1..*
Rucio 1.20.1.post1..*
Rucio 1.20.10..*
Rucio 1.20.11..*
Rucio 1.20.12..*
Rucio 1.20.13..*
Rucio 1.20.14..*
Rucio 1.20.15..*
Rucio 1.20.16..*
Rucio 1.20.2..*
Rucio 1.20.3..*
Rucio 1.20.3rc1..*
Rucio 1.20.3rc2..*
Rucio 1.20.4..*
Rucio 1.20.4.post1..*
Rucio 1.20.4.post2..*
Rucio 1.20.4rc1..*
Rucio 1.20.4rc2..*
Rucio 1.20.4rc3..*
Rucio 1.20.5..*
Rucio 1.20.6..*
Rucio 1.20.7..*
Rucio 1.20.8..*
Rucio 1.20.9..*
Rucio 1.21.0..*
Rucio 1.21.0.dev1..*
Rucio 1.21.0.post1..*
Rucio 1.21.0.post2..*
Rucio 1.21.0rc1..*
Rucio 1.21.0rc2..*
Rucio 1.21.0rc3..*
Rucio 1.21.1..*
Rucio 1.21.10..*
Rucio 1.21.10.post1..*
Rucio 1.21.12..*
Rucio 1.21.2..*
Rucio 1.21.3..*
Rucio 1.21.4..*
Rucio 1.21.5..*
Rucio 1.21.6..*
Rucio 1.21.7..*
Rucio 1.21.8..*
Rucio 1.22.0..*
Rucio 1.22.0.dev1..*
Rucio 1.22.0.dev2..*
Rucio 1.22.0.dev3..*
Rucio 1.22.0rc1..*
Rucio 1.22.0rc2..*
Rucio 1.22.1..*
Rucio 1.22.2..*
Rucio 1.22.3..*
Rucio 1.22.3.post1..*
Rucio 1.22.4..*
Rucio 1.22.4.dev1..*
Rucio 1.22.6..*
Rucio 1.22.6.post1..*
Rucio 1.22.7..*
Rucio 1.22.8.post1..*
Rucio 1.23.0..*
Rucio 1.23.0rc1..*
Rucio 1.23.0rc2..*
Rucio 1.23.1..*
Rucio 1.23.10..*
Rucio 1.23.11..*
Rucio 1.23.11.post1..*
Rucio 1.23.11.post2..*
Rucio 1.23.11.post3..*
Rucio 1.23.11.post4..*
Rucio 1.23.12..*
Rucio 1.23.13..*
Rucio 1.23.14..*
Rucio 1.23.15..*
Rucio 1.23.17..*
Rucio 1.23.18..*
Rucio 1.23.19..*
Rucio 1.23.2..*
Rucio 1.23.2.post1..*
Rucio 1.23.2.post2..*
Rucio 1.23.20..*
Rucio 1.23.4..*
Rucio 1.23.5..*
Rucio 1.23.5.post1..*
Rucio 1.23.6..*
Rucio 1.23.6.post1..*
Rucio 1.23.7..*
Rucio 1.23.7.post1..*
Rucio 1.23.8..*
Rucio 1.23.9..*
Rucio 1.23.9.post1..*
Rucio 1.23.9.post2..*
Rucio 1.23.9.post3..*
Rucio 1.23.9.post4..*
Rucio 1.24.0..*
Rucio 1.24.0rc1..*
Rucio 1.24.1..*
Rucio 1.24.1.post1..*
Rucio 1.24.1.post2..*
Rucio 1.24.1.post3..*
Rucio 1.24.1.post4..*
Rucio 1.24.2..*
Rucio 1.24.2.post1..*
Rucio 1.24.3..*
Rucio 1.24.3.post1..*
Rucio 1.24.4..*
Rucio 1.24.5..*
Rucio 1.24.5.post1..*
Rucio 1.25.0..*
Rucio 1.25.0rc1..*
Rucio 1.25.0rc2..*
Rucio 1.25.1..*
Rucio 1.25.1.post1..*
Rucio 1.25.2..*
Rucio 1.25.3..*
Rucio 1.25.3.post1..*
Rucio 1.25.3.post2..*
Rucio 1.25.4..*
Rucio 1.25.4.post1..*
Rucio 1.26.1.post1..*
Rucio 1.26.10..*
Rucio 1.26.11..*
Rucio 1.26.12..*
Rucio 1.26.13..*
Rucio 1.26.14..*
Rucio 1.26.15..*
Rucio 1.26.16..*
Rucio 1.26.17..*
Rucio 1.26.18..*
Rucio 1.26.2..*
Rucio 1.26.4..*
Rucio 1.26.5..*
Rucio 1.26.6..*
Rucio 1.26.7..*
Rucio 1.26.7.post1..*
Rucio 1.26.8..*
Rucio 1.26.8.post1..*
Rucio 1.26.9..*
Rucio 1.27.0..*
Rucio 1.27.0.post1..*
Rucio 1.27.0rc1..*
Rucio 1.27.0rc2..*
Rucio 1.27.1..*
Rucio 1.27.10..*
Rucio 1.27.11..*
Rucio 1.27.12..*
Rucio 1.27.2..*
Rucio 1.27.3..*
Rucio 1.27.4..*
Rucio 1.27.4.post1..*
Rucio 1.27.5..*
Rucio 1.27.7..*
Rucio 1.27.9..*
Rucio 1.28.0..*
Rucio 1.28.0rc1..*
Rucio 1.28.0rc2..*
Rucio 1.28.1..*
Rucio 1.28.2..*
Rucio 1.28.3..*
Rucio 1.28.4..*
Rucio 1.28.5..*
Rucio 1.28.6..*
Rucio 1.28.7..*
Rucio 1.29.0..*
Rucio 1.29.0rc1..*
Rucio 1.29.0rc2..*
Rucio 1.29.1..*
Rucio 1.29.10..*
Rucio 1.29.11..*
Rucio 1.29.12..*
Rucio 1.29.13..*
Rucio 1.29.14..*
Rucio 1.29.15..*
Rucio 1.29.16..*
Rucio 1.29.17..*
Rucio 1.29.18..*
Rucio 1.29.19..*
Rucio 1.29.2..*
Rucio 1.29.2.post1..*
Rucio 1.29.2.post2..*
Rucio 1.29.3.post1..*
Rucio 1.29.4..*
Rucio 1.29.5..*
Rucio 1.29.6..*
Rucio 1.29.7..*
Rucio 1.29.7.post1..*
Rucio 1.29.8..*
Rucio 1.29.9..*
Rucio 1.30.0..*
Rucio 1.30.0rc1..*
Rucio 1.30.0rc2..*
Rucio 1.30.0rc3..*
Rucio 1.30.1..*
Rucio 1.30.2..*
Rucio 1.30.3..*
Rucio 1.30.4..*
Rucio 1.30.5..*
Rucio 1.30.6..*
Rucio 1.30.7..*
Rucio 1.30.8..*
Rucio 1.31.0..*
Rucio 1.31.0rc1..*
Rucio 1.31.0rc2..*
Rucio 1.31.0rc3..*
Rucio 1.31.1..*
Rucio 1.31.2..*
Rucio 1.31.3..*
Rucio 1.31.4..*
Rucio 1.31.5..*
Rucio 1.31.6..*
Rucio 1.31.7..*
Rucio 32.0.0..*
Rucio 32.0.0rc1..*
Rucio 32.0.0rc2..*
Rucio 32.1.0..*
Rucio 32.2.0..*
Rucio 32.3.0..*
Rucio 32.3.1..*
Rucio 32.4.0..*
Rucio 32.5.0..*
Rucio 32.5.0.post1..*
Rucio 32.5.1..*
Rucio 32.6.0..*
Rucio 32.6.0.post1..*
Rucio 32.7.0..*
Rucio 32.8.0..*
Rucio 32.8.1..*
Rucio 32.8.2..*
Rucio 32.8.3..*
Rucio 32.8.4..*
Rucio 32.8.5..*
Rucio 32.8.6..*
Rucio 33.0.0..*
Rucio 33.0.0rc1..*
Rucio 33.0.0rc2..*
Rucio 33.0.0rc3..*
Rucio 33.1.0..*
Rucio 33.2.0..*
Rucio 33.2.1..*
Rucio 33.3.0..*
Rucio 33.4.0..*
Rucio 33.4.0.post1..*
Rucio 33.5.0..*
Rucio 33.6.0..*
Rucio 33.6.1..*
Rucio 34.0.0..*
Rucio 34.0.0rc1..*
Rucio 34.0.0rc2..*
Rucio 34.1.0..*
Rucio 34.2.0..*
Rucio 34.3.0..*
Rucio 34.4.0..*
Rucio 34.4.1..*
Rucio 34.4.2..*
Rucio 34.4.3..*
Rucio 34.5.0..*
Rucio 34.6.0..*
Rucio 35.0.0..*
Rucio 35.0.0rc1..*
Rucio 35.0.0rc2..*
Rucio 35.0.1..*
Rucio 35.1.0..*
Rucio 35.1.1..*
Rucio 35.2.0..*
Rucio 35.2.1..*
Rucio 35.3.0..*
Rucio 35.4.0..*
Rucio 35.4.1..*
Rucio 35.5.0..*
Rucio 35.6.0..*
Rucio 35.6.1..*
Rucio 35.7.0..*
Rucio 35.8.0..*
Rucio 35.8.1..*
Rucio 35.8.2..*
Rucio 35.8.3..*
Rucio 35.8.4..*
Rucio 35.8.5..*
Rucio 35.9.0..*
Rucio 36.0.0rc1..*
Rucio 36.0.0..*
Rucio 36.0.0.post1..*
Rucio 36.0.0.post2..*
Rucio 36.0.0rc2..*
Rucio 36.0.0rc3..*
Rucio 36.0.0rc4..*
Rucio 36.0.0rc5..*
Rucio 36.1.0..*
Rucio 36.2.0..*
Rucio 36.3.0..*
Rucio 36.4.0..*
Rucio 36.5.0..*
Rucio 37.0.0..*
Rucio 37.0.0rc1..*
Rucio 37.0.0rc2..*
Rucio 37.0.0rc3..*
Rucio 37.0.0rc4..*
Rucio 37.1.0..*
Rucio 37.1.0.post1..*
Rucio 37.2.0..*
Rucio 37.3.0..*
Rucio 37.4.0..*
Rucio 39.0.0rc1..*
Rucio 39.0.0..*
Rucio 39.0.0rc2..*
Rucio 39.1.0..*
Rucio 39.2.0..*
Rucio 39.3.0..*
Rucio 39.3.1..*
Rucio 39.4.0..*
Rucio 39.4.1..*
Rucio 39.4.2..*
Rucio 40.0.0..*
Rucio 40.0.0rc1..*
Rucio 40.1.0..*
Rucio 40.1.1..*
Rucio 40.1.2..*
Rucio 40.2.0..*
Rucio 40.3.0..*
Rucio 40.4.0..*
Rucio 40.4.1..*
Rucio 41.0.0rc1..*
Rucio 41.0.0..*
Rucio 41.1.0..*
Fixed in: Rucio 41.1.1
Rucio 40.4.2
Rucio 38.6.1
Rucio 35.9.1

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Metrics

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XIEM Effective CVSS

No value is available for this vulnerability.

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CVSS v3

No value is available for this vulnerability.

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EPSS score

No value is available for this vulnerability.

Show all metrics

Severity: Not rated
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: 30.00 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
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: 13.11.2026
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-287, CWE-305

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: Handle the vulnerability in regular vulnerability handling under Art. 21(2)(e) NIS2.
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

Summary

SSH challenge tokens are mistakenly accepted as valid credentials during the authentication token validation process.

While an SSH challenge token is intended as a short-lived nonce for use in a subsequent SSH key exchange, the function to validate authentication tokens does not differentiate between these and actual authentication tokens. Because challenge tokens are generated based on an account name provided via headers without requiring prior authentication, an unauthenticated attacker can request a valid "challenge" token for any account (including administrative ones) and use it to authenticate against other API endpoints.

Proof of Concept

The vulnerability exists because SSH challenge tokens are stored in the same database table as regular authentication tokens and validate_auth_token in lib/rucio/core/authentication.py accepts these "challenge" tokens. An attacker can obtain a challenge token for an account such as “root” via the REST API and then present it as a valid authentication bearer token:

Request a challenge token for an arbitrary account (e.g., "root"): curl -i -H "X-Rucio-Account: root" https://rucio/auth/ssh_challenge_token
The server returns a 200 OK with the header X-Rucio-SSH-Challenge-Token.
The attacker can then use this specific token within the ten-second challenge lifetime as an authentication credential in subsequent requests to the Rucio API: curl -H "X-Rucio-Auth-Token: $CHALLENGE_TOKEN" https://rucio/accounts/whoami

Source: OSV (Open Source Vulnerabilities), GitHub Security Advisories

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
pip	rucio	`>= 41.0.0rc1, < 41.1.1` `>= 1.14.0.post1, < 35.9.1` `>= 39.0.0rc1, < 40.4.2` `>= 36.0.0rc1, < 38.6.1`	`41.1.1` `35.9.1` `40.4.2` `38.6.1`
pypi	rucio	`1.24.2.post1` `1.21.2` `39.1.0` `1.29.11` `32.8.1` `34.1.0` `33.0.0` `1.30.0` `38.3.0` `36.0.0rc1` `35.5.0` `1.27.0rc2` `1.29.2.post1` `1.23.7` `1.21.8` `37.4.0` `1.31.2` `1.23.5` `1.20.10` `1.22.1` `1.26.7` `1.28.3` `1.29.0rc1` `33.0.0rc2` `1.23.2.post1` `1.20.5` `1.23.6` `32.0.0rc1` `1.31.4` `1.24.5.post1` `1.14.2` `1.16.2` `32.8.4` `1.23.11.post4` `1.23.0` `1.26.0` `33.4.0.post1` `1.25.1` `1.19.1` `1.21.0.post2` `32.4.0` `1.21.5` `1.27.12` `1.17.6.post1`	— — — — — — — — — `38.6.1` — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — —

Weakness classes (CWE)

CWE-287Improper Authentication
Class
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
Entry at MITRE CWE-287
CWE-305Authentication Bypass by Primary Weakness
Base
The authentication algorithm is sound, but the implemented mechanism can be bypassed as the result of a separate weakness that is primary to the authentication error.
Entry at MITRE CWE-305

References & sources

github.comrucio/rucio/security/advisories/GHSA-x585-4vv8-2mh2web
github.comrucio/rucio/commit/f5db3546d9c0de4642dc9aa52e6a6e447911d680web
github.comrucio/rucio/commit/e6525523e3bbe8ae34cbfc9b043ae52bda209b87web
github.comrucio/rucio/commit/d7a3c2c2f933dce8edbcad07d8d076b9b782da35web
github.comrucio/rucio/commit/b1725ee5477b683202174f0ec77ae00921bc3bd0web
github.comrucio/rucio/commit/883d526c2f3c315cd775fb142038007053e3882bweb
github.comrucio/rucio/commit/8295d72a9e2d76abf9e98eb6f9a4ed5cb3bb1869web
github.comrucio/rucio/commit/4df924feb539ef789b3e78cbc00712ef8cdf606eweb
github.comrucio/rucio/commit/4d4a58571ba853f3a55aef16ad9eb0944fce7483web
github.comrucio/rucio/releases/tag/35.9.1web
github.comrucio/rucio/releases/tag/35.9.1.post1web
github.comrucio/rucio/releases/tag/38.6.1web
github.comrucio/rucio/releases/tag/38.6.2web
github.comrucio/rucio/releases/tag/40.4.2web
github.comrucio/rucio/releases/tag/41.1.1web
github.comrucio/rucio/releases/tag/41.2.0web
github.comrucio/ruciopackage

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<a href="https://intel.neosec.eu/en/cve/CVE-2026-100397"><img src="https://intel.neosec.eu/badge/cve/CVE-2026-100397.svg?lang=en" alt="CVE-2026-100397 – NEOSEC Intel" height="20"></a>