Summary
Nginx UI: Standalone short tokens survive administrative revocation in cache and authenticate again after account re-enable
Standalone short tokens issued for WebSocket and explicit-token authentication can survive administrative revocation in cache. If the same account is later re-enabled before the cache entry expires, the deleted short token becomes valid again.
Details
GenerateShortToken() creates an AuthToken row that contains only ShortToken and no long Token. DeleteUserTokens() removes database rows, but when clearing caches it only invalidates entries where authToken.Token != "". This leaves standalone short-token cache entries behind. GetTokenUserByShortToken() checks that cache first and then loads the user by ID, so the stale short token becomes usable again if the account status is restored to true.
Relevant code paths:
- internal/user/user.go
- internal/user/user.go
- internal/user/user.go
- api/user/short_token.go
- internal/middleware/middleware.go
PoC
This was verfied locally in an isolated environment with a temporary package-level harness that exercised the real token issuance, revocation, cache, and re-authentication paths.
What the executed test did:
- Created an enabled user in a temporary SQLite database.
- Called the real
GenerateShortToken(user.ID)function to issue a standalone short token. - Verified that the token authenticated successfully and was present in the short-token cache.
- Disabled the user and called the real
DeleteUserTokens(user.ID)function. - Verified that the database token rows were removed.
- Verified that the short-token cache entry still existed after
DeleteUserTokens. - Re-enabled the same user.
- Reused the previously deleted short token via the real
GetTokenUserByShortToken()path and observed successful authentication.
Observed result from the actual local verification:
- The database token rows were removed during revocation.
- The short-token cache entry remained present.
- Re-enabling the user restored successful authentication through the stale short token.
Impact
Any deployment using standalone short tokens is affected. If a short token is stolen, administrative disable/delete-token handling may not fully revoke it. Re-enabling the account within the cache lifetime restores access for the stale token to any HTTP or WebSocket routes that accept short-token authentication.
CVE-2026-84321 has a CVSS score of 5.4 (Medium). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.9.10-0.20260703131214-23d1934099b0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2026-84321? CVE-2026-84321 is a medium-severity security vulnerability in github.com/0xJacky/Nginx-UI (go), affecting versions < 1.9.10-0.20260703131214-23d1934099b0. It is fixed in 1.9.10-0.20260703131214-23d1934099b0.
- How severe is CVE-2026-84321? CVE-2026-84321 has a CVSS score of 5.4 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of github.com/0xJacky/Nginx-UI are affected by CVE-2026-84321? github.com/0xJacky/Nginx-UI (go) versions < 1.9.10-0.20260703131214-23d1934099b0 is affected.
- Is there a fix for CVE-2026-84321? Yes. CVE-2026-84321 is fixed in 1.9.10-0.20260703131214-23d1934099b0. Upgrade to this version or later.
- Is CVE-2026-84321 exploitable, and should I be worried? Whether CVE-2026-84321 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-84321 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-84321? Upgrade
github.com/0xJacky/Nginx-UIto 1.9.10-0.20260703131214-23d1934099b0 or later.