6.1
MEDIUM CVSS 3.1
CVE-2026-73191
Apache Syncope: CAS service URL injection via Forwarded HTTP headers
Description

URL Redirection to Untrusted Site ('Open Redirect') vulnerability in Apache Syncope. When the Syncope SRA is configured for CAS authentication, the target Apereo CAS instance's URL is calculated by unconditionally looking at client-supplied forwarded HTTP headers. This issue affects Apache Syncope: from 3.0.0-M0 through 3.0.16, from 4.0.0-M0 Through 4.0.7, from 4.1.0-M0 through 4.1.2. Users are recommended to upgrade to version 4.0.8 / 4.1.3, which fix this issue.

INFO

Published Date :

Sept. 14, 2026, 2:17 p.m.

Last Modified :

Sept. 14, 2026, 8:58 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-73191 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Apache syncope
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 MEDIUM 134c704f-9b21-4f2e-91b3-4a467353bcc0
Solution
Upgrade Apache Syncope to a patched version to fix the open redirect vulnerability.
  • Upgrade Apache Syncope to version 4.0.8 or 4.1.3.
  • Ensure CAS authentication is configured securely.
  • Validate forwarded HTTP headers.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-73191.

URL Resource
https://lists.apache.org/thread/vx9bons1znhdkdpsxwjpy6qqqjc8xqtk
http://www.openwall.com/lists/oss-security/2026/09/14/5
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-73191 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-73191 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-73191 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-73191 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Sep. 14, 2026

    Action Type Old Value New Value
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
    Added SSVC {'id': 'CVE-2026-73191', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-09-14T19:32:24.226704Z'}
  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Sep. 14, 2026

    Action Type Old Value New Value
    Added Reference http://www.openwall.com/lists/oss-security/2026/09/14/5
  • New CVE Received by [email protected]

    Sep. 14, 2026

    Action Type Old Value New Value
    Added Description URL Redirection to Untrusted Site ('Open Redirect') vulnerability in Apache Syncope. When the Syncope SRA is configured for CAS authentication, the target Apereo CAS instance's URL is calculated by unconditionally looking at client-supplied forwarded HTTP headers. This issue affects Apache Syncope: from 3.0.0-M0 through 3.0.16, from 4.0.0-M0 Through 4.0.7, from 4.1.0-M0 through 4.1.2. Users are recommended to upgrade to version 4.0.8 / 4.1.3, which fix this issue.
    Added CWE CWE-601
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/73xxx/CVE-2026-73191.json">CVE-2026-73191</a>
    Added Reference https://lists.apache.org/thread/vx9bons1znhdkdpsxwjpy6qqqjc8xqtk
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.