# CVE-2026-95508: Libslirp: libslirp: heap buffer overflow in dhcpv6/tftp response builders on small interface mtu

Status: published. Published: 2026-09-22. Updated: 2026-11-03.

A heap-based buffer overflow was found in the DHCPv6 and TFTP response builders of libslirp. When the host is configured with a small interface MTU, a guest-supplied DHCPv6 CLIENTID option or TFTP blksize option can overflow the reply buffer with attacker-controlled content and length, resulting in denial of service and potentially arbitrary code execution in the host process. The default interface MTU is not affected.

## Remediation

- workaround: Do not configure SlirpConfig.if_mtu below the IPv6 minimum link MTU of 1280. (source: CNA: redhat)

## Affected products and versions

- Red Hat / Red Hat Enterprise Linux 10 (libslirp): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8 (container-tools:rhel8/libslirp): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (libslirp): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (libslirp): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openshift/ose-rhel-coreos-8): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openshift/ose-rhel-coreos-9): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 5 (openshift/ose-rhel-coreos-9): Version range not reported. Source: CNA: redhat

## Severity and prioritization

- CVSS 3.1: 7.4 (high); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H; source: CNA: redhat

- CVSS 3.1: 7.4 (high); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H; source: NVD: secalert@redhat.com

- CISA KEV: No listing in collected sources

- EPSS: 0.57% as of 2026-11-02; percentile 47.19%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-787

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://access.redhat.com/security/cve/CVE-2026-95508 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2537748 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

- https://access.redhat.com/security/cve/CVE-2026-95508 (secalert@redhat.com)

- https://bugzilla.redhat.com/show_bug.cgi?id=2537748 (secalert@redhat.com)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2026-95508; retrieved 2026-11-03; source updated 2026-11-03

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-95508; retrieved 2026-11-03; source updated 2026-11-03

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-95508; retrieved 2026-11-03; source updated Not reported

Revision: 1fed86be7839354e4a06b9fbef71b806931d7a2c52704b8e9bff1c0473b5439c

Canonical: https://y2.dev/cve/CVE-2026-95508

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