CVE-2026-84321: Nginx UI: Standalone short tokens survive administrative revocation in cache and authenticate again after account re-enable
Vulnerability summary
CVE-2026-84321 is a medium (CVSS 5.4) vulnerability in 0xjacky nginx-ui. EPSS estimates a 0.21% chance of exploitation in the next 30 days, higher than 11.2% of scored vulnerabilities.
Not severe (CVSS 5.4, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Timeline
- 12-10-2026PublishedVulnerability first disclosed.
- 13-10-2026Last modifiedVulnerability information updated.
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.
CVSS metrics
3 scores · 3 sources · 1 version- CVE.orgCNA5.4MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
- OSV · GoEcosystem advisory · calculated5.4MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
EPSS trend
Probability
0.21%
Chance of exploitation in the next 30 days
Percentile
11%
Versus all other CVEs
30-day change
Change unavailable
Change unavailable
Known exploited
Compare KEV catalogsNot in the CISA KEV catalog.
Not in the ENISA CNW catalog.
Not in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
0xjacky1 product
- nginx-ui< 2.4.1
Github.com/0xJacky1 product
- Nginx-UI< 1.9.10-0.20260703131214-23d1934099b0
2 vendors · 2 products
References
5 links- github.com/0xJacky/nginx-uiPACKAGE