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High 7.0Published Oct 23, 2026

CVE-2026-57209Heimdall: Forwarded Header Injection via Unsanitized Host Header in Proxy Mode

Updated under an hour ago ()

Does this affect you?

It affects dadrus heimdall. Add what you run to find out whether that includes you.

EPSS puts the chance of exploitation in the next 30 days at 0.34%, higher than 27% of scored CVEs.

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.

CVSS
7.0 HIGH (v4.0, CNA)CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N
Weakness (CWE)
CWE-20, CWE-74
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
0.34% (percentile 27)
Assigned by
GitHub_M
NVD analysis
Deferred
Record last updated
Oct 23, 2026
First seen by InfoSec Signals
Oct 23, 2026

Affected products

Affected products
dadrus heimdall
dadrus:heimdall (from the name)
before 0.17.17
CNA record

References

References

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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