Poweradmin Host Header Injection in OIDC/SAML Callback URL Construction
CVE-2026-54588 is a critical host header injection vulnerability in Poweradmin, a web-based DNS administration tool for PowerDNS. In versions prior to 4.2.4 and 4.3.3, the application uses the attacker-controlled HTTP_HOST request header as the authoritative source when constructing authentication-related callback URLs, including OIDC redirect_uri, SAML ACS and SLO URLs, and logout redirect destinations, without validating that header against a trusted canonical host. Because these URLs are then supplied to the Identity Provider during authentication flows, an unauthenticated remote attacker can poison the callback destination so that the IdP returns the victim’s authorization code or related authentication response to an attacker-controlled server. This can lead to full account takeover without requiring the attacker to know the victim’s credentials.
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Impact, mitigation & remediation
What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.
Impact
What an attacker gets, and what they’ve been doing with it.
Mitigation
If you can’t patch tonight, do this now.
Host/HTTP_HOST values, and ensuring IdP-side redirect/callback URL allowlists are tightly restricted to the legitimate Poweradmin origin. Review OIDC and SAML configuration to confirm ACS, SLO, logout, and redirect URIs are statically defined where possible rather than dynamically derived from inbound headers.Remediation
Patch, then assume compromise.
Exploits
No public exploits tracked yet. Mallory keeps watching.
No public exploit code observed for this vulnerability.
Recent activity
5 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
The version that knows your environment.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.