CVE-2026-23140

MEDIUMCVSS 5.5/10EPSS 0.12%

Last modified

CVE-2026-23140 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: bpf, test_run: Subtract size of xdp_frame from allowed metadata size The xdp_frame structure takes up part of the XDP frame headroom, limiting the size of the metadata. However, in bpf_test_run, we don't take this into account, which makes it possible for userspace to supply a metadata size that is too large (taking up the entire headroom). If userspace supplies such a large metadata size in live packet mode, the xdp_update_frame_from_buff() call in xdp_test_run_init_page() call will fail, after which packet transmission proceeds with an uninitialised frame structure, leading to the usual Bad Stuff. The commit in the Fixes tag fixed a related bug where the second check in xdp_update_frame_from_buff() could fail, but did not add any additional constraints on the metadata size. EPSS estimates a 0.12% chance of exploitation in the next 30 days.

Description

In the Linux kernel, the following vulnerability has been resolved: bpf, test_run: Subtract size of xdp_frame from allowed metadata size The xdp_frame structure takes up part of the XDP frame headroom, limiting the size of the metadata. However, in bpf_test_run, we don't take this into account, which makes it possible for userspace to supply a metadata size that is too large (taking up the entire headroom). If userspace supplies such a large metadata size in live packet mode, the xdp_update_frame_from_buff() call in xdp_test_run_init_page() call will fail, after which packet transmission proceeds with an uninitialised frame structure, leading to the usual Bad Stuff. The commit in the Fixes tag fixed a related bug where the second check in xdp_update_frame_from_buff() could fail, but did not add any additional constraints on the metadata size. Complete the fix by adding an additional check on the metadata size. Reorder the checks slightly to make the logic clearer and add a comment.

Metrics

CVSS 3.1
5.5/10

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

EPSS Probability
0.12%

2.3th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

VendorProductVersionsUpdate
LinuxLinux Kernel>= 5.18, < 6.1.161
LinuxLinux Kernel>= 6.2, < 6.6.121
LinuxLinux Kernel>= 6.7, < 6.12.66
LinuxLinux Kernel>= 6.13, < 6.18.6
LinuxLinux Kernel6.19Rc1

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-23140?
In the Linux kernel, the following vulnerability has been resolved: bpf, test_run: Subtract size of xdp_frame from allowed metadata size The xdp_frame structure takes up part of the XDP frame headroom, limiting the size of the metadata. However, in bpf_test_run, we don't take this into account, which makes it possible for userspace to supply a metadata size that is too large (taking up the entire headroom). If userspace supplies such a large metadata size in live packet mode, the xdp_update_frame_from_buff() call in xdp_test_run_init_page() call will fail, after which packet transmission proceeds with an uninitialised frame structure, leading to the usual Bad Stuff. The commit in the Fixes tag fixed a related bug where the second check in xdp_update_frame_from_buff() could fail, but did not add any additional constraints on the metadata size. Complete the fix by adding an additional check on the metadata size. Reorder the checks slightly to make the logic clearer and add a comment.
How severe is CVE-2026-23140?
CVE-2026-23140 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.12% probability of exploitation in the next 30 days.
How do I fix CVE-2026-23140?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-23140?

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Source: NVD / NIST