---
title: "CVE-2026-54588: Poweradmin has Host Header Injection in OIDC redirect_uri, SAML ACS/SLO URL, and Logout Redirect Construction."
url: https://erroneo.us/security/cve/CVE-2026-54588/
description: "CVE-2026-54588 (poweradmin/poweradmin (Composer (PHP))): Poweradmin is a web-based DNS administration tool for PowerDNS server. Versions prior to 4.2.4 and…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-06-23
date_modified: 2026-07-28
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-54588"
kev: false
cvss: 9.6
epss: 0.00543
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-54588: Poweradmin has Host Header Injection in OIDC redirect_uri, SAML ACS/SLO URL, and Logout Redirect Construction.

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.5% , percentile 45: FIRST’s model estimates a 0.5% chance of exploitation activity in the next 30 days, higher than 45% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Needs a user to click or open something. Phishing makes that realistic, but it is not wormable.
- Only applies if your dependency tree includes poweradmin/poweradmin (Composer (PHP)) < 4.2.4, fixed in 4.2.4 ; poweradmin/poweradmin (Composer (PHP)) >= 4.3.0, < 4.3.3, fixed in 4.3.3 . Check your lockfile, including transitive dependencies.

## What it is

Poweradmin is a web-based DNS administration tool for PowerDNS server. Versions prior to 4.2.4 and 4.3.3 use the attacker-controlled HTTPHOST request header as the authoritative source for building callback URLs in its OIDC, SAML, and logout authentication flows without any validation. An unauthenticated attacker can poison the redirecturi sent to the Identity Provider, causing the IdP to redirect the victim's authorization code to an attacker-controlled server - resulting in full account takeover with no credentials required. Versions 4.2.4 and 4.3.3 patch the issue.

## Affected packages

- Composer (PHP) `poweradmin/poweradmin` < 4.2.4 → fixed: 4.2.4
- Composer (PHP) `poweradmin/poweradmin` >= 4.3.0, < 4.3.3 → fixed: 4.3.3

## Affected products (CVE record)

- poweradmin poweradmin: < 4.2.4, >= 4.3.0, < 4.3.3

## Severity

- GitHub_M CVSS 3.1: 9.6 `CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L`
- GitHub CVSS 3.1: 9.6 `CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable no , technical impact partial .
- FIRST EPSS (model of 2026-10-21): 0.54% probability of exploitation activity in the next 30 days; percentile 45.

## Sources

- [GitHub Advisory GHSA-3735-5339-xfwx](https://github.com/advisories/GHSA-3735-5339-xfwx)
- [CVE.org record CVE-2026-54588](https://www.cve.org/CVERecord?id=CVE-2026-54588)
- [NVD entry CVE-2026-54588](https://nvd.nist.gov/vuln/detail/CVE-2026-54588)
- [github.com](https://github.com/poweradmin/poweradmin/security/advisories/GHSA-3735-5339-xfwx)
- [github.com](https://github.com/poweradmin/poweradmin/releases/tag/v4.2.4)
- [github.com](https://github.com/poweradmin/poweradmin/releases/tag/v4.3.3)

---
Source page: https://erroneo.us/security/cve/CVE-2026-54588/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt