CVE-2026-81881 radareorg CVE debrief

Who should care

Defenders responsible for radare2 installations, particularly those using versions prior to 6.2.0, should assess exposure and prioritize upgrading to the fixed version. This includes operators, platform administrators, vulnerability management teams, and security teams who need to ensure the security and integrity of systems using radare2.

Why it matters

Defenders should prioritize verifying and upgrading to radare2 version 6.2.0 or later to mitigate this vulnerability, as it can cause incorrect metadata processing or process termination when parsing crafted Mach-O files.

• Potential process termination due to incorrect metadata processing
• Possible incorrect metadata processing leading to unexpected behavior

Technical summary

The radare2 Mach-O Swift field-metadata parser vulnerability occurs when parsing Swift type and class metadata from a crafted Mach-O file, potentially causing incorrect metadata processing or process termination. The vulnerability arises from a relative Swift field pointer that could be lower than the field-metadata section base, leading to a negative logical index. This results in reading four bytes immediately before the allocated field-metadata buffer, which can cause incorrect metadata processing or process termination.

Defensive priority

Defenders should prioritize verifying and upgrading to radare2 version 6.2.0 or later to mitigate this vulnerability.

Recommended defensive actions

• Verify radare2 version and upgrade to 6.2.0 or later
• Review and update affected systems and tools
• Monitor for potential exploitation attempts
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• 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 vulnerability is triggered by parsing Swift type and class metadata from a crafted Mach-O file, which can cause incorrect metadata processing or process termination. No attacker-observable memory disclosure has been demonstrated. The issue arises from a relative Swift field pointer that could be lower than the field-metadata section base, leading to a negative logical index. This results in reading four bytes immediately before the allocated field-metadata buffer.

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.