CVE-2026-95508 Red Hat CVE debrief

Who should care

Defenders and administrators responsible for systems and networks using libslirp should assess exposure and prioritize patching, especially in environments with untrusted or guest-accessible networks.

Why it matters

CVE-2026-95508 is a heap-based buffer overflow vulnerability in libslirp that can lead to denial of service and potentially arbitrary code execution. Defenders should prioritize verifying and patching libslirp installations, especially in environments with untrusted or guest-accessible networks.

• Denial of service due to buffer overflow
• Potential arbitrary code execution in the host process
• Need for verification of libslirp installations and patches
• Potential impact on systems with small interface MTU

Technical summary

The vulnerability exists in the DHCPv6 and TFTP response builders of libslirp. A guest-supplied DHCPv6 CLIENTID option or TFTP blksize option can overflow the reply buffer with attacker-controlled content and length when the host has a small interface MTU, leading to denial of service and potentially arbitrary code execution in the host process. The default interface MTU is not affected. Defenders should prioritize verifying and patching libslirp installations, especially in environments with untrusted or guest-accessible networks.

Defensive priority

Defenders should prioritize verifying and patching libslirp installations, especially in environments with untrusted or guest-accessible networks.

Recommended defensive actions

• Verify and apply patches for libslirp
• Assess and limit exposure of libslirp installations
• Monitor for potential denial of service and code execution 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 details on the heap-based buffer overflow vulnerability in libslirp. Red Hat has a reference page for this CVE. The vulnerability affects systems with small interface MTU. Defenders should verify libslirp installations and patches, especially in environments with untrusted or guest-accessible networks. The CVE Program and NVD provide official records and assessments.

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.