CVE-2026-63926 Details
Description
In the Linux kernel, the following vulnerability has been resolved: bpf: sockmap: fix tail fragment offset in bpf_msg_push_data When bpf_msg_push_data() inserts data in the middle of a scatterlist entry, it splits the original entry into a left fragment and a right fragment. The right fragment offset is page-local, but the code advances it with `start`, which is the message-global insertion point. For inserts into a non-first SG entry, this over-advances the offset and leaves the split layout inconsistent. Advance the right fragment offset by the fragment-local delta, `start - offset`, which matches the length removed from the front of the original entry.
A vulnerability exists in the Linux kernel's BPF sockmap implementation, specifically within the 'bpf_msg_push_data' helper function. This issue arises when data is inserted into the middle of a scatterlist entry, causing the entry to split into left and right fragments. The right fragment's offset is page-local, but the code incorrectly advances it using the message-global insertion point. This misalignment creates an inconsistent layout, particularly for inserts into non-first scatterlist entries. The vulnerability has been addressed by adjusting the right fragment offset to reflect the correct fragment-local delta, ensuring a consistent split layout.
Users can upgrade to the latest version of the Linux kernel where this vulnerability has been fixed.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
No SSVC data is available for this CVE.
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Weakness Enumeration
No weakness enumeration is available for this CVE.
Affected Products
No affected product data is available for this CVE.
Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 20, 2026 | CVE Modified | kernel.org |
| Jul 19, 2026 | New CVE Received | kernel.org |