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

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-120831
StatePUBLISHED
Assignerredhat
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-11-03 02:16:53 UTC
Updated2026-11-03 15:17:25 UTC
DescriptionA 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.

Risk And Classification

Primary CVSS: v3.1 6.5 MEDIUM from [email protected]

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

EPSS: 0.002650000 probability, percentile 0.185190000 (date 2026-11-03)

Problem Types: CWE-787 | CWE-787 Out-of-bounds Write

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary6.5MEDIUMCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
3.1CNACVSS6.5MEDIUMCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS v3.1 Breakdown

Attack Vector
Adjacent
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

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

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Red Hat Red Hat Enterprise Linux 10 Not specified Not specified
CNA Red Hat Red Hat Enterprise Linux 8 Not specified Not specified
CNA Red Hat Red Hat Enterprise Linux 9 Not specified Not specified
CNA Red Hat Red Hat OpenShift Container Platform 4 Not specified Not specified
CNA Red Hat Red Hat OpenShift Container Platform 4 Not specified Not specified
CNA Red Hat Red Hat OpenShift Container Platform 4 Not specified Not specified
CNA Red Hat Red Hat OpenShift Container Platform 5 Not specified Not specified

References

ReferenceSourceLinkTags
access.redhat.com/security/cve/CVE-2026-120831 [email protected] access.redhat.com
bugzilla.redhat.com/show_bug.cgi [email protected] bugzilla.redhat.com
gitlab.freedesktop.org/slirp/libslirp/-/commit/bad35bd3b529dc47aa109980a69a36da7848ab76 [email protected] gitlab.freedesktop.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Red Hat would like to thank Piyusha Akash (Manifold Operations) for reporting this issue. (en)

Additional Advisory Data

SourceTimeEvent
CNA2026-10-10T00:00:00.000ZReported to Red Hat.
CNA2026-10-30T00:00:00.000ZMade public.

Workarounds

CNA: 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.

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