CVE-2026-84321

MEDIUMCVSS 5.4/10EPSS 0.21%

Last modified

CVE-2026-84321 is a medium-severity vulnerability rated 5.4/10 on the CVSS scale. 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. EPSS estimates a 0.21% chance of exploitation in the next 30 days.

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.

Metrics

EPSS Probability
0.21%

10.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
0xJackynginx-ui< 2.4.1

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is CVE-2026-84321?
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.
How severe is CVE-2026-84321?
CVE-2026-84321 has a CVSS score of 5.4/10 (MEDIUM severity). The EPSS model estimates a 0.21% probability of exploitation in the next 30 days.
How do I fix CVE-2026-84321?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST