Red Hat Enterprise Linux/OpenShift Container Platform libslirp if_output denial of service

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.0$0-$5k3.15

Summaryinfo

A vulnerability has been found in Red Hat Enterprise Linux and OpenShift Container Platform and classified as critical. This impacts the function if_output of the component libslirp. This manipulation causes denial of service. This vulnerability appears as CVE-2026-120831. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability was found in Red Hat Enterprise Linux and OpenShift Container Platform (the affected version unknown). It has been declared as critical. Affected by this vulnerability is the function if_output of the component libslirp. The manipulation with an unknown input leads to a denial of service vulnerability. The CWE definition for the vulnerability is CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. As an impact it is known to affect availability. The summary by CVE is:

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.

The advisory is shared at access.redhat.com. This vulnerability is known as CVE-2026-120831 since 11/03/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 11/03/2026). MITRE ATT&CK project uses the attack technique T1499 for this issue.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-115656). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

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Vendor

Name

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.0
VulDB Meta Temp Score: 7.0

VulDB Base Score: 7.5
VulDB Temp Score: 7.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 6.5
CNA Vector (redhat): 🔒

CVSSv2info

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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Denial of service
CWE: CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

11/03/2026 Advisory disclosed
11/03/2026 +0 days CVE reserved
11/03/2026 +0 days VulDB entry created
11/03/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: redhat.com

Advisory: access.redhat.com
Status: Not defined

CNA: redhat
CVE: CVE-2026-120831 (🔒)

GCVE (CVE): GCVE-0-2026-120831
GCVE (VulDB): GCVE-100-430153
EUVD: 🔒

Entryinfo

Created: 11/03/2026 03:23
Updated: 11/03/2026 04:50
Changes: 11/03/2026 03:23 (62), 11/03/2026 04:50 (1)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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