CVE-2026-25885: polarnl PolarLearn · Improper Authorization
Affects polarnl PolarLearnSource CVE Database V5
Not known to be exploited · CVSS 10.0 Critical : upgrade to 0-PRERELEASE-16 as a priority.
Data as of 26 Oct 2026, 07:57 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 26% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 0-PRERELEASE-16
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:LExploitation evidence
Disclosed: evidence found.
CVE published 9 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.
What to do
Upgrade polarnl PolarLearn to 0-PRERELEASE-16.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| polarnlPolarLearn | Affected
| Fixed in
|
AI-suggested
1. Upgrade PolarLearn to versions beyond 0-PRERELEASE-16 as soon as a patched release is available to ensure proper authorization checks on WebSocket connections. 2. If you cannot patch yet, implement network-level controls such as Web Application Firewalls (WAFs) or reverse proxies to enforce authentication on the WebSocket endpoint, blocking unauthenticated access. 3. Restrict access to the WebSocket API by IP whitelisting or VPN requirements to limit exposure to trusted users only. 4. Monitor WebSocket traffic for anomalous subscription or message patterns indicative of unauthorized access or message injection. 5. Conduct thorough audits of group chat content to identify and remove unauthorized messages and assess potential data leakage. 6. Educate users about the risk of misinformation and encourage reporting of suspicious messages. 7. Implement logging and alerting on WebSocket connection attempts and message submissions to detect exploitation attempts early. 8. Review and enhance access control mechanisms in the application codebase to prevent similar authorization bypass issues in other components. 9. Coordinate with the PolarLearn development community to track patch releases and share threat intelligence. 10. Prepare incident response plans specific to chat system compromise scenarios to minimize operational impact.
Description
CVE-2026-25885 is a critical improper authorization vulnerability in PolarLearn versions prior to 0-PRERELEASE-16. It allows unauthenticated attackers to connect to the group chat WebSocket endpoint and subscribe to or send messages in any group chat by supplying a group UUID. This flaw enables attackers to inject unauthorized messages that are stored persistently, not just displayed temporarily, leading to potential misinformation, disruption, or data integrity issues. The vulnerability requires no authentication or user interaction and can be exploited remotely over the network. The CVSS 4.0 base score is 10, reflecting its critical severity due to full network exploitability and high impact on confidentiality, integrity, and availability. European organizations using PolarLearn for educational or collaborative purposes are at risk of unauthorized data manipulation and privacy breaches. Mitigation involves upgrading to versions beyond 0-PRERELEASE-16 once available or implementing strict access controls and WebSocket authentication proxies. Countries with significant adoption of PolarLearn or similar open-source educational platforms, such as the Netherlands, Germany, France, and the UK, are most likely to be affected. Given the critical nature and ease of exploitation, immediate attention is required to prevent abuse and maintain trust in collaborative learning environments.