Vulnerability in Linux kernel (CVE-2026-98803)
Summary
Vulnerability in Linux kernel (CVE-2026-98803). 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 rx Scatter-Gather support
When a received frame is larger than dma_buf_sz, the DMA scatters it
across multiple RX descriptors (rx Scatter-Gather). The secondary RX
buffer (sec_page) was only allocated and programmed when split-header
(SPH) was active, so for regular frames buffer2 was neither allocated
nor backed by a valid mapping. As soon as an incoming frame overflowed
buffer1, the DMA wrote the overflow into the unmapped secondary-buffer
address, triggering an SMMU translation fault on IOMMU-based platforms:
arm-smmu 15000000.iommu: Unhandled context fault: fsr=0x402, iova=0x00000000, fsynr=0x7f0011, cbfrsynra=0x1c90, cb=11
arm-smmu 15000000.iommu: FSR = 00000402 [Format=2 TF], SID=0x1c90
arm-smmu 15000000.iommu: FSYNR0 = 007f0011 [S1CBNDX=127 WNR PLVL=1]
Enable scatter-gather for non-SPH frames on cores that can program an
independent secondary RX buffer (GMAC4/XGMAC): allocate and mark buffer2
as valid in stmmac_init_rx_buffers() and stmmac_rx_refill(), and account
for it in the buffer length computation. Legacy cores have no set_sec_addr
op, so they keep buffer2 disabled.
Since buffer2 is handed to the DMA at page offset 0, the page pool sync
window is widened to cover both buffers in every mode: offset is set to 0
and max_len to dma_buf_sz + stmmac_rx_offset().
The FCS can straddle the buffer1/buffer2 boundary and a descriptor
boundary, so it is now stripped from the tail of…
Source: NIST National Vulnerability Database 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-2026-98803 has been found in Linux kernel.
Risk of unauthorized operations or information disclosure.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2026-98803" on the vendor's site.
CVE-2026-98803 (Linux kernel)
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: ?. 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。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-98803 linux
References
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web nvd.nist.gov
- web github.com