CVE-2019-12250
IdentityServer IdentityServer4 through 2.4 has stored XSS via the httpContext to the host/Extensions/RequestLoggerMiddleware.cs LogForErrorContext method, which can be triggered by viewing a log.
Does this matter?
Lower severity and a low EPSS score (0.85%). Track it; it rarely justifies an emergency change on its own.
Description
IdentityServer IdentityServer4 through 2.4 has stored XSS via the httpContext to the host/Extensions/RequestLoggerMiddleware.cs LogForErrorContext method, which can be triggered by viewing a log. NOTE: the software maintainer disputes that this is a vulnerability because the request logger is not part of IdentityServer but only our development test host
- CVSS 3.0
- 6.1 MEDIUMCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- EPSS
- 0.85% probability · 58th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-79
- Affected
- identityserver/identityserver4
- Source
- cve@mitre.org
EPSS 0.8% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/IdentityServer/IdentityServer4/issues/3279Exploit, Third Party Advisory
- https://github.com/IdentityServer/IdentityServer4/issues/3279Exploit, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.