---
title: "CVE-2026-120830: libslirp - Information Disclosure"
description: "libslirp contains an out-of-bounds read caused by improper length handling in icmp_forward_error() when building ICMP error responses, letting attackers leak host memory via malformed IPv4 packets, exploit requires sending crafted packets."
url: https://panop.io/threat-heartbeat/CVE-2026-120830/
---

# CVE-2026-120830 libslirp - Information Disclosure

libslirp contains an out-of-bounds read caused by improper length handling in icmp\_forward\_error() when building ICMP error responses, letting attackers leak host memory via malformed IPv4 packets, exploit requires sending crafted packets.

CVSS base score 7.4 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-120830)

## Details

Type

Information Disclosure

Impact

Information Disclosure

CVSS vector

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N

Published

3 November 2026

Updated

3 November 2026

Weakness

[CWE-125](https://cwe.mitre.org/data/definitions/125.html)

## Vendor fix

Update libslirp to the latest version containing the fix.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-120830](https://nvd.nist.gov/vuln/detail/CVE-2026-120830)
- [https://gitlab.freedesktop.org/slirp/libslirp/-/commit/21b33a6c5588af9f58d15e528fdc1019452708e4](https://gitlab.freedesktop.org/slirp/libslirp/-/commit/21b33a6c5588af9f58d15e528fdc1019452708e4)
- [https://access.redhat.com/security/cve/CVE-2026-120830](https://access.redhat.com/security/cve/CVE-2026-120830)
- [https://bugzilla.redhat.com/show\_bug.cgi?id=2565424](https://bugzilla.redhat.com/show_bug.cgi?id=2565424)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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