UBUNTU-CVE-2026-120830: High severity ubuntu/libslirp vulnerability
Published Nov 3, 2026
·Updated
A flaw was found in libslirp in icmpforwarderror(). When building an ICMP error response, the length of the quoted original IPv4 packet was taken from the IP header without clamping it to the actual buffer length. A truncated or malformed packet could cause an out-of-bounds heap read, leaking host memory into the ICMP error packet returned to a guest or container.
Affected Software
5 affected components
ubuntu/libslirp*
ubuntu/libslirp*
ubuntu/libslirp*
ubuntu/libslirp*
ubuntu/libslirp*
Event History
Nov 3, 2026
CVE Published
via OSV·12:00 AM
Data Sourced
via OSV·12:00 AM
DescriptionSeverityAffected Software
Frequently Asked Questions
1
What level of attacker access is required?
The attack vector is adjacent network access. It requires no privileges and no user interaction.
2
Who can receive the leaked data?
Host memory may be included in an ICMP error packet returned to a guest or container. The affected component is Ubuntu's libslirp.
3
Does this issue allow modification or denial of service?
The provided impact information identifies high confidentiality impact, with no integrity or availability impact.