CVE-2026-57209
Heimdall is a cloud native Identity Aware Proxy and Access Control Decision service
- Risk score
- 55/100
- CVSS
- 7.0 v4.0
- Exploit chance (30 days)
- 0.5%
- Published
- 23 Oct 2026
Open in the live forecast Today's forecast
What to know
- What it is
- 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 inserting the incoming request's Host header value directly into the header string wi…
- Affected
- See advisory
- Fix
- Upgrade the product to 0.17.17 or later.
- Exploitation
- No known exploitation
Why it is Yellow
- CVSS 7.0 high
- Remotely exploitable without logging in
References
Original description
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 inserting the incoming request's Host header value directly into the header string without sanitizing commas or semicolons. This allows an attacker to inject additional parameters into the Forwarded header, potentially spoofing IP addresses for upstream services. This issue has been patched in version 0.17.17.
Last activity 23 Oct 2026. Patch Forecast updates every hour.