CVE-2026-110642 xhtml2pdf CVE debrief

Who should care

Defenders responsible for systems using the xhtml2pdf library, particularly those using the pisa tool with the -s or --start-viewer option, should be aware of this vulnerability and take steps to mitigate it.

Why it matters

The xhtml2pdf library before version 0.2.19 contains an OS command injection vulnerability that allows attackers to execute OS commands. Defenders should prioritize upgrading to a patched version and review system logs for suspicious activity.

• Potential for attackers to execute arbitrary OS commands
• Possible impact on system security and integrity
• Need for defenders to verify and upgrade to a patched version

Technical summary

The xhtml2pdf library before version 0.2.19 contains an OS command injection vulnerability in the pisa.startViewer() function. This vulnerability allows attackers to execute OS commands by providing a specially crafted file name that interpolates unescaped shell metacharacters. The vulnerability is triggered when the pisa tool is used with the -s or --start-viewer option. Affected product deployments should be reviewed for exposure, and defenders should prioritize upgrading to version 0.2.19 or later of the xhtml2pdf library to mitigate this vulnerability.

Defensive priority

Defenders should prioritize upgrading to version 0.2.19 or later of the xhtml2pdf library to mitigate this vulnerability. Additionally, defenders should review their systems for any suspicious activity related to the pisa tool and ensure that all input files are properly sanitized.

Recommended defensive actions

• Upgrade to version 0.2.19 or later of the xhtml2pdf library
• Review system logs for suspicious activity related to the pisa tool
• Ensure that all input files are properly sanitized
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed
• Check relevant monitoring, detection, and logs for exposed assets that need extra review

Evidence notes

The CVE record and source item provide details about the vulnerability, including its description, affected versions, and references to patches and advisories. However, there is limited information about the vulnerability's impact and exploitation.

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.