CVE-2026-17591 Red Hat CVE debrief

Who should care

Defenders responsible for systems using libarchive should assess the potential impact of this vulnerability and prioritize verification and remediation efforts. Defenders should prioritize verifying the presence of this vulnerability in their systems, especially those using libarchive, and assess the potential impact of a DoS or information disclosure.

Why it matters

The use-after-free vulnerability in libarchive can cause a Denial of Service (DoS) or potential information disclosure, requiring defenders to verify the presence of this vulnerability in their systems and assess the potential impact.

• Potential Denial of Service (DoS) due to application crashes
• Potential information disclosure through reading uninitialized memory data
• Need for verification of libarchive version and vulnerability presence
• Prioritization of remediation efforts based on system criticality

Technical summary

The archive_entry_copy_mac_metadata() function in libarchive deallocates an internal buffer before completing a data copy, leading to a use-after-free vulnerability. An attacker can cause a Denial of Service (DoS) or potential information disclosure by supplying input to an application utilizing this function. The flaw can cause a Denial of Service (DoS) or potential information disclosure. This issue arises when the archive_entry_copy_mac_metadata() function deallocates an internal buffer before completing a data copy.

Defensive priority

Defenders should prioritize verifying the presence of this vulnerability in their systems, especially those using libarchive, and assess the potential impact of a DoS or information disclosure.

Recommended defensive actions

• Verify the presence of this vulnerability in systems using libarchive
• Assess the potential impact of a DoS or information disclosure
• Review and update libarchive to the latest version if necessary
• 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 NVD entry provide details about the vulnerability, but the scope of affected systems and versions is not explicitly stated. Further verification is needed to determine the extent of the vulnerability.

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.