CVE-2026-75828 getgrav CVE debrief

Who should care

Defenders and administrators of Grav installations should assess exposure and prioritize remediation to prevent exploitation. This includes reviewing and updating incident response plans, conducting regular security audits, and implementing additional security measures to detect and prevent exploitation. Security teams should also monitor for suspicious activity and implement compensating controls to mitigate potential impacts.

Why it matters

CVE-2026-75828 is a stored cross-site scripting vulnerability in Grav before 2.0.15 that allows authenticated editors to inject event handlers, potentially leading to execution in visitor browsers. Defenders should prioritize verifying exposure and applying patches or workarounds to prevent exploitation.

• Potential for authenticated editors to inject malicious event handlers
• Execution of event handlers in visitor browsers when page content is rendered
• Possible impact on visitor browsers and potential for further exploitation

Technical summary

The detectXss() function in Grav before 2.0.15 contains a stored cross-site scripting vulnerability where unpaired quotes in unquoted attribute values bypass event-handler detection. Authenticated editors can inject event handlers like onerror= that pass validation and execute in visitor browsers when page content is rendered. This vulnerability allows attackers to inject malicious scripts, potentially leading to unauthorized actions and data breaches. The vulnerability is caused by inadequate input validation and sanitization in the detectXss() function.

Defensive priority

Defenders should prioritize verifying exposure and applying patches or workarounds to prevent exploitation.

Recommended defensive actions

• Verify exposure by checking Grav versions and configurations
• Apply patches or workarounds to prevent exploitation
• Monitor for suspicious activity and implement compensating controls
• Review and update incident response plans to address potential exploitation
• Conduct regular security audits to identify and remediate vulnerabilities
• Implement additional security measures, such as web application firewalls, to detect and prevent exploitation
• Track and analyze logs for signs of potential exploitation

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, but vendor remediation and affected versions require verification. The vulnerability was discovered in Grav before 2.0.15, and defenders should verify exposure and apply patches or workarounds to prevent exploitation. Evidence from the CVE record and NVD entry suggests that authenticated editors can inject event handlers, but the full scope of affected versions and configurations is not explicitly stated.

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.