Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:NCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-32301 is a critical-severity SSRF (CWE-918) vulnerability in Centrifugal Centrifugo. Its CVSS base score is 9.3 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 30th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to AC-4 (Information Flow Enforcement) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-32301 is a Server-Side Request Forgery (SSRF) vulnerability (CWE-918) in Centrifugo, an open-source scalable real-time messaging server. It affects versions prior to 6.7.0 when configured with a dynamic JSON Web Key Set (JWKS) endpoint URL that uses template variables, such as {{tenant}}. In this setup, claim values from a JSON Web Token (JWT) are interpolated into the JWKS fetch URL before the token's signature verification occurs.
An unauthenticated attacker can exploit the vulnerability by crafting a JWT with malicious iss or aud claim values. These values cause Centrifugo to fetch the JWKS from an attacker-controlled destination via an outbound HTTP request. The CVSS v3.1 base score is 9.3 (AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N), reflecting critical severity with network accessibility, low attack complexity, no privileges or user interaction required, changed scope, high confidentiality impact, and low integrity impact.
The vulnerability is fixed in Centrifugo version 6.7.0. Additional details on mitigation and patches are available in the GitHub security advisory at https://github.com/centrifugal/centrifugo/security/advisories/GHSA-j77h-rr39-c552.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-11716
Vulnerability Data
Centrifugo is an open-source scalable real-time messaging server. Prior to 6.7.0, Centrifugo is vulnerable to Server-Side Request Forgery (SSRF) when configured with a dynamic JWKS endpoint URL using template variables (e.g. {{tenant}}). An unauthenticated attacker can craft a JWT with…
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a malicious iss or aud claim value that gets interpolated into the JWKS fetch URL before the token signature is verified, causing Centrifugo to make an outbound HTTP request to an attacker-controlled destination. This vulnerability is fixed in 6.7.0.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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Mitigating Controls (NIST 800-53 r5) AI
Information flow enforcement can restrict which destinations the server is allowed to contact on behalf of users.
Input validation directly stops untrusted URLs from being accepted and fetched without destination checks.
Boundary protection limits the network reach of server-initiated requests even if SSRF occurs.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure development practices directly include input validation and destination allow-listing that prevent SSRF.
Runtime monitoring of web applications and services can detect anomalous outbound requests indicative of SSRF.
Vulnerability identification processes can discover and record SSRF flaws in web applications.
Network segmentation and egress controls can limit the damage from successful SSRF requests.