CVE-2026-110686 RURBAN CVE debrief

Who should care

Defenders responsible for Perl applications using Cpanel::JSON::XS should assess exposure and prioritize remediation. This includes operators, platform administrators, vulnerability management teams, and security teams who need to verify the version of Cpanel::JSON::XS in use and apply the patch or update to version 4.80 or later.

Why it matters

Defenders should care about CVE-2026-110686 because it can cause process crashes or issues with Perl applications using Cpanel::JSON::XS versions before 4.80. The vulnerability requires verification of the version in use and application of a patch or update to version 4.80 or later. The impact is potentially significant, with possible denial of service or instability in affected systems.

• Potential process crashes or issues with Perl applications using Cpanel::JSON::XS versions before 4.80
• Need to verify version of Cpanel::JSON::XS in use and apply patch or update
• Potential for denial of service or instability in affected systems

Technical summary

Cpanel::JSON::XS versions before 4.80 for Perl use freed filter callbacks when a filter removes itself during decoding in decode_hv. A decode copies the parser's filter_json_object and filter_json_single_key_object callbacks without taking references to them. A filter callback that removes the last single-key filter frees the callback table while the decode in progress still uses it. The next object is dispatched through freed memory and can crash the process.

Defensive priority

Defenders should prioritize verifying the version of Cpanel::JSON::XS in use and applying the patch or updating to version 4.80 or later.

Recommended defensive actions

• Verify the version of Cpanel::JSON::XS in use
• Apply the patch or update to version 4.80 or later
• Monitor for potential crashes or issues with the Perl process
• 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 source item provide details on the vulnerability, including a description of the issue and affected versions. The vulnerability requires verification of the version in use and application of a patch or update to version 4.80 or later. The impact is potentially significant, with possible denial of service or instability in affected systems. Defenders should verify the version of Cpanel::JSON::XS in use and apply the patch or update to version 4.80 or later.

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.