CVE-2026-23083
Use-After-Free in Linux Kernel FOU Component Due to Invalid IPPROTO
Publication date: 2026-02-04
Last updated on: 2026-03-18
Assigner: kernel.org
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | 6.19 |
| linux | linux_kernel | 6.19 |
| linux | linux_kernel | 6.19 |
| linux | linux_kernel | 6.19 |
| linux | linux_kernel | 6.19 |
| linux | linux_kernel | From 5.11 (inc) to 5.15.199 (exc) |
| linux | linux_kernel | From 5.16 (inc) to 6.1.162 (exc) |
| linux | linux_kernel | From 6.2 (inc) to 6.6.122 (exc) |
| linux | linux_kernel | From 6.7 (inc) to 6.12.68 (exc) |
| linux | linux_kernel | From 6.13 (inc) to 6.18.8 (exc) |
| linux | linux_kernel | 6.19 |
| linux | linux_kernel | From 3.18 (inc) to 5.10.249 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in the Linux kernel's handling of the FOU (Foo Over UDP) protocol attribute FOU_ATTR_IPPROTO. Specifically, if the FOU_ATTR_IPPROTO is set to 0, the function fou_udp_recv() does not properly free the associated socket buffer (skb) nor resubmit it in ip_protocol_deliver_rcu(). This improper handling can lead to resource management issues. The fix involves forbidding the value 0 for FOU_ATTR_IPPROTO to prevent this problem.
How can this vulnerability impact me? :
If FOU_ATTR_IPPROTO is set to 0, the Linux kernel's fou_udp_recv() function fails to free the socket buffer or resubmit it properly. This can lead to resource leaks or unexpected behavior in network packet processing, potentially causing system instability or degraded performance.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
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What immediate steps should I take to mitigate this vulnerability?
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