CVE-2026-95508 PUBLISHED

Libslirp: libslirp: heap buffer overflow in dhcpv6/tftp response builders on small interface mtu

Assigner: redhat
Reserved: 22.09.2026 Published: 22.09.2026 Updated: 22.09.2026

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.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H
CVSS Score: 7.4

Product Status

Vendor Red Hat
Product Red Hat Enterprise Linux 10
Versions Default: affected
Vendor Red Hat
Product Red Hat Enterprise Linux 8
Versions Default: affected
Vendor Red Hat
Product Red Hat Enterprise Linux 9
Versions Default: affected
Vendor Red Hat
Product Red Hat OpenShift Container Platform 4
Versions Default: affected
Vendor Red Hat
Product Red Hat OpenShift Container Platform 4
Versions Default: affected
Vendor Red Hat
Product Red Hat OpenShift Container Platform 4
Versions Default: affected

Workarounds

Do not configure SlirpConfig.if_mtu below the IPv6 minimum link MTU of 1280.

Credits

  • Red Hat would like to thank Stuart Thomas for reporting this issue.

References

Problem Types

  • Out-of-bounds Write CWE