CVE-2026-78190 ASPEER CVE debrief

Who should care

Defenders responsible for WebDyne deployments, particularly those using versions 2.014 to 3.022, should assess exposure and prioritize remediation. They should review the vendor's remediation guidance and verify the exposure of affected systems. Additionally, defenders should monitor for crafted links and script injection attempts, and review compensating controls for exposed systems.

Why it matters

CVE-2026-78190 is a cross-site scripting vulnerability in WebDyne that allows remote attackers to inject script into any page. Defenders should prioritize verifying exposure and applying vendor remediation.

• Remote attackers can inject script into any page using crafted links
• Defenders must verify exposure of WebDyne versions 2.014 to 3.022
• Remediation requires upgrading to WebDyne version 3.022 or later

Technical summary

The textfield, password_field, and filefield tags in WebDyne versions from 2.014 before 3.022 for Perl reflect request parameters unescaped into form field values. The WEBDYNE_CGI_AUTOESCAPE setting, which controls escaping of these values, defaults to off and is ineffective due to changes in WebDyne::HTML::Tiny's entity_encode method. This allows remote attackers to inject script into any page using crafted links. Defenders should prioritize verifying exposure of WebDyne versions 2.014 to 3.022 and applying vendor remediation.

Defensive priority

Defenders should prioritize verifying exposure of WebDyne versions 2.014 to 3.022 and applying vendor remediation.

Recommended defensive actions

• Verify WebDyne versions 2.014 to 3.022 are in use and assess exposure
• Apply vendor remediation to upgrade to WebDyne version 3.022 or later
• Monitor for crafted links and script injection attempts
• 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
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD entry provide limited information about the vulnerability. The Metacpan reference provides additional context about the WebDyne version changes. Defenders should verify the exposure of WebDyne versions 2.014 to 3.022 and review the vendor's remediation guidance. The vulnerability allows remote attackers to inject script into any page using textfield, password_field, and filefield tags through crafted links. WebDyne::HTML::Tiny's entity_encode method returns its input unchanged, making the WEBDYNE_CGI_AUTOESCAPE

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.