CVE-2026-89246 WWBN CVE debrief

Who should care

Defenders and administrators of AVideo instances should assess exposure and prioritize remediation, especially in systems where administrators or video owners have access to exported CSV files.

Why it matters

The CVE-2026-89246 vulnerability in AVideo's myComments.download.php endpoint allows authenticated users to inject spreadsheet formulas, which execute when administrators or video owners open exported CSV files. Defenders should prioritize verifying and remediating this vulnerability, especially in systems where administrators or video owners have access to exported CSV files. The vulnerability's scope and remediation require verification from official sources.

• Execution of arbitrary spreadsheet formulas when administrators or video owners open exported CSV files
• Potential for data tampering or unauthorized actions through injected formulas
• Verification of vulnerability existence and scope in AVideo instances
• Remediation priority for systems with high administrator or video owner access to exported CSV files

Technical summary

The myComments.download.php endpoint in AVideo fails to sanitize spreadsheet formula prefixes in comment text, allowing authenticated users to inject formulas starting with =, +, -, or @ characters. This vulnerability can lead to execution of arbitrary spreadsheet formulas when administrators or video owners open exported CSV files, potentially resulting in data tampering or unauthorized actions through injected formulas. Defenders should prioritize verifying and remediating this vulnerability, especially in systems where administrators or video owners have access to exported CSV files.

Defensive priority

Defenders should prioritize verifying and remediating this vulnerability, especially in systems where administrators or video owners have access to exported CSV files.

Recommended defensive actions

• Verify the vulnerability exists in your AVideo instance
• Restrict access to the myComments.download.php endpoint
• Sanitize user input in comment text
• Monitor for suspicious activity in exported CSV files
• 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 CVE record and NVD entry provide details on the vulnerability. Verification from official sources is required to determine the scope and remediation. The vulnerability's existence and scope in AVideo instances should be verified, and remediation should be prioritized, especially in systems with high administrator or video owner access to exported CSV files.

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.