CVE-2026-99017: Linux kernel · riscv: errata: select RISCV_ALTERNATIVE_EARLY for THEAD GHOSTWRITE
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.0 High.
Data as of 28 Oct 2026, 01:44 UTC
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 23 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10linuxpkg:deb/ubuntu/linux?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-oraclepkg:deb/ubuntu/linux-oracle?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix is available by selecting RISCV_ALTERNATIVE_EARLY from ERRATA_THEAD_GHOSTWRITE to ensure the vulnerability is detected during the early boot stage and the mitigation is applied. Users should update to kernel versions where this fix is implemented or ensure their kernel configuration includes this selection to enable proper mitigation.
Description
A vulnerability in the Linux kernel's RISC-V architecture handling involves improper detection and mitigation of the THEAD GHOSTWRITE erratum. The issue arises because the mitigation is only applied if the CPU vulnerability is detected during an early boot stage enabled by a specific configuration flag. If the kernel is built with ERRATA_THEAD_GHOSTWRITE enabled but ERRATA_THEAD_MAE disabled, the vulnerability is not detected, leaving the system unprotected despite being vulnerable. This affects certain Linux kernel versions and can lead to high impact on confidentiality, integrity, and availability.
References
- ubuntu.com/security/CVE-2026-99017 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-99017 (opens in a new tab)
- git.kernel.org/stable/c/298510bbc7c3017c0faf481c6ea66f1065b657b4 (opens in a new tab)
- git.kernel.org/stable/c/7fee577a2fa78b9a76da015beec1ccf978746ebb (opens in a new tab)
- git.kernel.org/stable/c/fa465a7819ecbe5801b78c088d3cadaf2664b8ca (opens in a new tab)