CVE-2026-120831: libslirp · Out-of-bounds Write
Source GCVE Database
Not known to be exploited · CVSS 6.5 Medium.
Data as of 3 Nov 2026, 03:59 UTC
Thin evidence
One scorer or none| CNA (redhat) | CVSS 3.1 | 6.5 |
|---|
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 3 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Red Hat Enterprise Linux 10libslirp | Affected– | Fixed in– |
| Red Hat Enterprise Linux 8container-tools:rhel8/libslirp | Affected– | Fixed in– |
| Red Hat Enterprise Linux 9libslirp | Affected– | Fixed in– |
| Red Hat OpenShift Container Platform 4libslirp | Affected– | Fixed in– |
| Red Hat OpenShift Container Platform 4openshift/ose-rhel-coreos-8 | Affected– | Fixed in– |
| Red Hat OpenShift Container Platform 4openshift/ose-rhel-coreos-9 | Affected– | Fixed in– |
AI-suggested
Red Hat currently does not have a practical temporary workaround that fully mitigates this issue. Customers are advised to apply relevant security updates when they become available. Monitoring Red Hat advisories for patch releases is recommended.
Description
A vulnerability in libslirp's if_output() function causes queue pointer corruption when moving a session from the fast queue to the batch queue. This flaw can lead to a denial of service by crashing the host networking process if a guest generates burst traffic.
References
- nvd.nist.gov/vuln/detail/CVE-2026-120831 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-120831 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2565425 (opens in a new tab)
- gitlab.freedesktop.org/slirp/libslirp/-/commit/bad35bd3b529dc47aa109980a69a36da7848ab76 (opens in a new tab)