CVE-2026-84321

Nginx UI: Standalone short tokens survive administrative revocation in cache and authenticate again after account re-enable

MEDIUM
5.4
CVSS Score
Published: October 12, 2026 at 08:49 PM UTC
Updated: October 13, 2026 at 04:17 PM UTC
1 product affected across 1 vendornginx UI

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Severity
MEDIUM5.4
Exploit prediction
EPSS 0.2%
SSVC
PoC

Description

Nginx UI is a web user interface for the Nginx web server. Prior to 2.4.1, GenerateShortToken creates standalone short-token records without a long Token value, but DeleteUserTokens invalidates cached entries only when the long Token field is nonempty. A revoked short token can therefore remain in the short_token cache and authenticate again if the associated account is re-enabled before the cache entry expires because GetTokenUserByShortToken reads the surviving entry, restoring access to HTTP or WebSocket routes that accept short-token authentication. This issue is fixed in version 2.4.1.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 2.4.1

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.4MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-613

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