Quick answers
- Is CVE-2026-120830 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-120830 being exploited in the wild.
- How severe is CVE-2026-120830?
- High severity, with a CVSS score of 7.4, published 3 November 2026.
- Which products and versions are affected?
- freedesktop libslirp.
- Is there a fix for CVE-2026-120830?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-120830 attacked?
- It is attacked from the adjacent network, in a software library.
- Am I affected by CVE-2026-120830?
- Check whether you run Freedesktop Libslirp. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
The vulnerability exists in the icmp_forward_error() function, which builds ICMP error responses without clamping the quoted original IPv4 packet length to the actual buffer size. A truncated or malformed packet causes an out-of-bounds heap read from the host process memory. Attack requires network-adjacent access (a guest or container with network capability), no authentication or user interaction.
Affected products
- freedesktop libslirp
Timeline
- 2026-11-03: disclosed