Linux Kernel up to 6.6.121/6.12.67/6.18.7/6.19-rc6 fou fou_udp_recv privilege escalation

CVSS Meta Temp Score
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CTI Interest Score
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6.5$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.6.121/6.12.67/6.18.7/6.19-rc6. This vulnerability affects the function fou_udp_recv of the component fou. The manipulation leads to an unknown weakness. This vulnerability is listed as CVE-2026-23083. There is no available exploit. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.6.121/6.12.67/6.18.7/6.19-rc6. It has been rated as critical. This issue affects the function fou_udp_recv of the component fou. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: fou: Don't allow 0 for FOU_ATTR_IPPROTO. fou_udp_recv() has the same problem mentioned in the previous patch. If FOU_ATTR_IPPROTO is set to 0, skb is not freed by fou_udp_recv() nor "resubmit"-ted in ip_protocol_deliver_rcu(). Let's forbid 0 for FOU_ATTR_IPPROTO.

It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2026-23083 since 01/13/2026. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 05/03/2026).

The vulnerability scanner Nessus provides a plugin with the ID 297900 (Linux Distros Unpatched Vulnerability : CVE-2026-23083), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.6.122, 6.12.68, 6.18.8 or 6.19-rc7 eliminates this vulnerability. Applying the patch 1cc98b8887cabb1808d2f4a37cd10a7be7574771/b7db31a52c3862a1a32202a273a4c32e7f5f4823/9b75dff8446ec871030d8daf5a69e74f5fe8b956/7a9bc9e3f42391e4c187e099263cf7a1c4b69ff5 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (297900), SecurityFocus (BID 0†) and CERT Bund (WID-SEC-2026-0324). Be aware that VulDB is the high quality source for vulnerability data.

Affected

  • Debian Linux
  • Google Cloud Platform
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • IBM QRadar SIEM
  • SUSE openSUSE
  • RESF Rocky Linux
  • Open Source Linux Kernel

Productinfo

Type

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Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.6
VulDB Meta Temp Score: 6.5

VulDB Base Score: 5.5
VulDB Temp Score: 5.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 7.8
NVD Vector: 🔒

CVSSv2info

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

Exploitinginfo

Class: Privilege escalation
CWE: Unknown
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 297900
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-23083

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.6.122/6.12.68/6.18.8/6.19-rc7
Patch: 1cc98b8887cabb1808d2f4a37cd10a7be7574771/b7db31a52c3862a1a32202a273a4c32e7f5f4823/9b75dff8446ec871030d8daf5a69e74f5fe8b956/7a9bc9e3f42391e4c187e099263cf7a1c4b69ff5

Timelineinfo

01/13/2026 CVE reserved
02/04/2026 +22 days Advisory disclosed
02/04/2026 +0 days VulDB entry created
05/03/2026 +88 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-23083 (🔒)
GCVE (CVE): GCVE-0-2026-23083
GCVE (VulDB): GCVE-100-344303
SecurityFocus: 0
CERT Bund: WID-SEC-2026-0324 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 02/04/2026 18:08
Updated: 05/03/2026 12:32
Changes: 02/04/2026 18:08 (59), 02/06/2026 10:16 (7), 02/07/2026 12:13 (2), 03/18/2026 14:59 (12), 05/03/2026 12:32 (1)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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