CVE-2026-55840
Scoold: Open Redirect in getBackToUrl() allows phishing via domain-prefix startsWith bypass
Description
Scoold is a Q&A and a knowledge sharing platform for teams. Prior to 1.69.1, the getBackToUrl() method in src/main/java/com/erudika/scoold/utils/HttpUtils.java validates the backto and returnto parameters with Strings.CI.startsWith against the configured server URL. An attacker can supply an absolute URL whose hostname begins with the legitimate hostname, causing URI.resolve() to retain the attacker URL and the prefix check to accept it. A victim who follows the crafted sign-in link can be redirected to an attacker-controlled domain after authentication, enabling phishing and possible credential or token theft. This issue is fixed in version 1.69.1.
INFO
Published Date :
Oct. 15, 2026, 7:17 p.m.
Last Modified :
Oct. 15, 2026, 9:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | MITRE-CVE | ||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update Scoold to version 1.69.1 or later.
- Verify the server URL configuration.
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-2026-55840.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-55840 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-2026-55840
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-2026-55840 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-55840 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
Oct. 15, 2026
Action Type Old Value New Value Added Reference https://github.com/Erudika/scoold/security/advisories/GHSA-85fm-6f2v-74pq Added SSVC {'id': 'CVE-2026-55840', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-10-15T20:15:05.964680Z'} -
New CVE Received by [email protected]
Oct. 15, 2026
Action Type Old Value New Value Added Description Scoold is a Q&A and a knowledge sharing platform for teams. Prior to 1.69.1, the getBackToUrl() method in src/main/java/com/erudika/scoold/utils/HttpUtils.java validates the backto and returnto parameters with Strings.CI.startsWith against the configured server URL. An attacker can supply an absolute URL whose hostname begins with the legitimate hostname, causing URI.resolve() to retain the attacker URL and the prefix check to accept it. A victim who follows the crafted sign-in link can be redirected to an attacker-controlled domain after authentication, enabling phishing and possible credential or token theft. This issue is fixed in version 1.69.1. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N Added CWE CWE-601 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/55xxx/CVE-2026-55840.json">CVE-2026-55840</a> Added Reference https://github.com/Erudika/scoold/commit/9d61f6fe15d4f9f6262812ba7fea43be8d5bb745 Added Reference https://github.com/Erudika/scoold/releases/tag/1.69.1 Added Reference https://github.com/Erudika/scoold/security/advisories/GHSA-85fm-6f2v-74pq