Summary
vulnerability in linux (CVE-2026-43039). Successful exploitation can lead to full system takeover.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
net: ti: icssg-prueth: fix missing data copy and wrong recycle in ZC RX dispatch
emac_dispatch_skb_zc() allocates a new skb via napi_alloc_skb() but
never copies the packet data from the XDP buffer into it. The skb is
passed up the stack containing uninitialized heap memory instead of
the actual received packet, leaking kernel heap contents to userspace.
Copy the received packet data from the XDP buffer into the skb using
skb_copy_to_linear_data().
Additionally, remove the skb_mark_for_recycle() call since the skb is
backed by the NAPI page frag allocator, not page_pool. Marking a
non-page_pool skb for recycle causes the free path to return pages to
a page_pool that does not own them, corrupting page_pool state.
The non-ZC path (emac_rx_packet) does not have these issues because it
uses napi_build_skb() to wrap the existing page_pool page directly,
requiring no copy, and correctly marks for recycle since the page comes
from page_pool_dev_alloc_pages().
Source: NIST National Vulnerability Database NVD
AI summary
Written by an external AI model and may contain mistakes. Check the original description and references below before acting on it.
This vulnerability in the Linux kernel could lead to critical data leakage, allowing attackers to view data without user consent. Immediate action is required as similar issues have historically had significant impacts. It is recommended to update to the fixed version immediately.
The Linux kernel function "emac_dispatch_skb_zc" has a vulnerability where it fails to copy data from the XDP buffer to the skb, leading to potential leaks of uninitialized memory to user space. The fix involves using "skb_copy_to_linear_data" to correctly copy the data. This vulnerability is highly critical with a CVSS score of 9.8, allowing remote attacks without authentication. Immediate patching is strongly advised.
Vulnerability where "emac_dispatch_skb_zc" fails to copy data, leading to potential kernel heap leakage.
Linux kernel's "emac_dispatch_skb_zc" function in net: ti: icssg-prueth.
CVSS score 9.8: critical, remote attack possible, no authentication needed.
Apply patch using "skb_copy_to_linear_data" to properly copy packet data.
No specific workaround presented, immediate patching recommended.
Check if systems use "emac_dispatch_skb_zc" and verify patch application.
Related past incidents Similar incidents extracted from past CVEs
OpenSSL vulnerability leaking memory, similar data leak risk.
Vulnerability in OpenSSL causing memory leak, similar leakage of sensitive data.
Heap overflow vulnerability in sudo, similar memory exploitation Risk.
If this happens at your company Expected impact per business scenario
Sensitive data might be exposed to unauthorized entities, compromising system integrity.
Potential data breaches leading to customer loss and reputational damage.
Risk of intellectual property theft due to data exposure.
Update Linux kernel to the version containing the security patch addressing this specific vulnerability immediately.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'linux' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
linuxを grep し、稼働しているサービス・バージョンを把握する。 -
7Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番では Step 3 と同じログクエリでアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-43039 linux Fixed in: 6.19.12-1
- Ubuntu UBUNTU-CVE-2026-43039 linux-hwe-edge
References
- advisory github.com
- advisory nvd.nist.gov
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org