CVE-2026-57209Published

Heimdall: Forwarded Header Injection via Unsanitized Host Header in Proxy Mode

Collected exploitation and prediction evidence

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

Dated risk observations

Risk history is separate from CNA/OSV content history. Daily score drift is retained but only an upward crossing of 10% triggers the prediction change event.

Immutable source observations

4 recorded revisions

Each citation identifies one complete source statement. Source modification dates and the time this installation observed them are distinct. Latest history includes records historically associated by source identifiers; a removed alias is not a current equivalence claim. Exact citations show that source record's own earlier observations. Failed reads and unchanged polls do not rewrite history.

25 Oct 2026 14:19:10 UTC

Heimdall is a cloud native Identity Aware Proxy and Access Control Decision service. Prior to version 0.17.17, when Heimdall operates in proxy mode, it constructs the Forwarded HTTP header after executing the matched rule pipeline by insert…

nvd · CVE-2026-57209 · Published

24 Oct 2026 13:19:41 UTC