CVE-2026-31941 chamilo CVE debrief

Who should care

Defenders responsible for Chamilo LMS instances, particularly those with the Social Wall feature enabled, should assess exposure and apply patches to prevent SSRF attacks. This includes reviewing system configurations, verifying version numbers, and ensuring that appropriate security measures are in place to protect against potential attacks. Additionally, security teams should monitor for suspicious activity and implement compensating controls as needed.

Why it matters

CVE-2026-31941 is a high-severity SSRF vulnerability in Chamilo LMS that allows authenticated attackers to make arbitrary HTTP requests. Defenders should prioritize verifying exposure and applying patches to prevent potential attacks.

• Authenticated attackers can make arbitrary HTTP requests to internal services
• Internal port scanning is possible
• Access to cloud instance metadata is potentially exposed
• Verification of Chamilo LMS version and patch application is required

Technical summary

The Chamilo LMS Social Wall feature contains a Server-Side Request Forgery (SSRF) vulnerability. The read_url_with_open_graph endpoint accepts user-supplied URLs without validation, allowing authenticated attackers to force the server to make arbitrary HTTP requests to internal services, scan internal ports, and access cloud instance metadata. This vulnerability is fixed in versions 1.11.38 and 2.0.0-RC.3.

Defensive priority

Defenders should prioritize verifying exposure and applying patches to Chamilo LMS instances, particularly those with the Social Wall feature enabled.

Recommended defensive actions

• Verify Chamilo LMS version and apply patches to vulnerable instances
• Restrict access to the Social Wall feature to trusted users
• Monitor server logs for suspicious HTTP requests
• Implement additional security measures to detect and prevent SSRF attacks
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The vulnerability is confirmed in Chamilo LMS versions prior to 1.11.38 and 2.0.0-RC.3. The Social Wall feature's read_url_with_open_graph endpoint accepts user-supplied URLs without validation, leading to SSRF.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.