Vulnerability in Linux kernel (CVE-2026-45940)
Summary
Vulnerability in Linux kernel (CVE-2026-45940). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
net: stmmac: fix oops when split header is enabled
For GMAC4, when split header is enabled, in some rare cases, the
hardware does not fill buf2 of the first descriptor with payload.
Thus we cannot assume buf2 is always fully filled if it is not
the last descriptor. Otherwise, the length of buf2 of the second
descriptor will be calculated wrong and cause an oops:
Unable to handle kernel paging request at virtual address ffff00019246bfc0
...
x2 : 0000000000000040 x1 : ffff00019246bfc0 x0 : ffff00009246c000
Call trace:
dcache_inval_poc+0x28/0x58 (P)
dma_direct_sync_single_for_cpu+0x38/0x6c
__dma_sync_single_for_cpu+0x34/0x6c
stmmac_napi_poll_rx+0x8f0/0xb60
__napi_poll.constprop.0+0x30/0x144
net_rx_action+0x160/0x274
handle_softirqs+0x1b8/0x1fc
...
To fix this, the PL bit-field in RDES3 register is used for all
descriptors, whether it is the last descriptor or not.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-45940 has been found in Linux kernel.
Risk of unauthorized operations or information disclosure. CVSS score: 5.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2026-45940" on the vendor's site.
CVE-2026-45940 (Linux kernel) — CVSS v3 5.5
Attack vector: local / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (unclassified) exists in Linux kernel.
Check the vendor advisory for the affected versions of Linux kernel.
Severity: Medium (CVSS 5.5/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Linux kernel を使っているサービスとバージョンを洗い出す。
-
2Post-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。本番ではアクセスログ・WAF 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
- BellSoft Alpaquita BELL-CVE-2026-45940 linux-lts
- Debian DEBIAN-CVE-2026-45940 linux
- Ubuntu UBUNTU-CVE-2026-45940 linux-hwe-edge
References
- advisory nvd.nist.gov
- advisory github.com
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web github.com