CVE-2026-110673 RURBAN CVE debrief

Who should care

Defenders responsible for Perl applications using Cpanel::JSON::XS should assess exposure and prioritize updating to version 4.80 or later. This includes operators, platform administrators, vulnerability management teams, and security teams. They should review and monitor JSON input processing for potential stack exhaustion attacks and implement compensating controls to detect and prevent excessive stack usage.

Why it matters

CVE-2026-110673 is a vulnerability in Cpanel::JSON::XS that allows stack exhaustion via nested tagged values. Defenders should prioritize verifying and updating Cpanel::JSON::XS to version 4.80 or later to prevent potential attacks.

• Potential denial-of-service (DoS) due to stack exhaustion
• Possible remote code execution via crafted JSON inputs
• Need for verification of Cpanel::JSON::XS version and JSON input processing
• Priority on updating to version 4.80 or later to prevent exploitation

Technical summary

Cpanel::JSON::XS versions before 4.80 for Perl allow stack exhaustion via nested tagged values under allow_tags in decode_tag. This vulnerability can cause a segmentation fault due to stack exhaustion when processing specific JSON inputs. The vulnerability is triggered when the allow_tags option is used, and a run of '(' bytes can exhaust the C stack. The technical impact is a potential denial-of-service (DoS) due to stack exhaustion. Defenders should prioritize verifying and updating Cpanel::JSON::XS to version 4.80 or later to prevent potential stack exhaustion attacks.

Defensive priority

Defenders should prioritize verifying and updating Cpanel::JSON::XS to version 4.80 or later to prevent potential stack exhaustion attacks.

Recommended defensive actions

• Verify Cpanel::JSON::XS version and update to 4.80 or later if necessary
• Review and monitor JSON input processing for potential stack exhaustion attacks
• Implement compensating controls to detect and prevent excessive stack usage
• 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 on the vulnerability, including its description and affected versions. However, the CVSS score and severity are not provided. The vulnerability is in Cpanel::JSON::XS versions before 4.80 for Perl. The source item and CVE record provide evidence of the vulnerability's existence and its potential impact. Defenders should verify the Cpanel::JSON::XS version and JSON input processing to prevent potential attacks.

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.