CVE-2026-120831

Libslirp: libslirp: queue pointer corruption in if_output() leading to denial of service

Published Nov 3, 2026 CVSS 3.1 · 6.5 Medium EPSS < 1% KEV · Not listed
Description
A flaw was found in libslirp in if_output(). When moving a session from the fast queue to the batch queue, the code unlinked and reinserted an arbitrary packet via ifm->m_nextpkt instead of the session queue head, corrupting queue pointers. A guest generating burst traffic could crash the host networking process, causing a denial of service.

Remediation

Vendor Workaround

Red Hat is not aware of a practical temporary workaround that fully mitigates this issue or meets Red Hat Product Security's standards for usability, deployment, applicability, or stability. Customers are advised to apply the relevant security updates when/if they become available.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
CPEs cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
cpe:/a:redhat:enterprise_linux:10
cpe:/a:redhat:enterprise_linux:8
cpe:/a:redhat:enterprise_linux:9
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description A flaw was found in libslirp in if_output(). When moving a session from the fast queue to the batch queue, the code unlinked and reinserted an arbitrary packet via ifm->m_nextpkt instead of the session queue head, corrupting queue pointers. A guest generating burst traffic could crash the host networking process, causing a denial of service.
Title Libslirp: libslirp: queue pointer corruption in if_output() leading to denial of service
First Time appeared Redhat
Redhat enterprise Linux
Redhat openshift
Weaknesses CWE-787
CPEs cpe:/a:redhat:openshift:4
cpe:/a:redhat:openshift:5
cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux
Redhat openshift
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
redhat
Published
Updated
Nov 5, 2026, 7:03 PM
Reserved
Nov 2, 2026, 11:39 PM
Status
Awaiting Analysis
Published
Nov 3, 2026, 2:16 AM
Modified
Nov 5, 2026, 7:17 PM
Severity
Moderate
Public date
Oct 30, 2026, 12:00 AM