CVE-2026-99017: Linux kernel · riscv: errata: select RISCV_ALTERNATIVE_EARLY for THEAD GHOSTWRITE
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.0 High · fixed in fa465a7819ecbe5801b78c088d3cadaf2664b8ca : patch Linux kernel soon.
Data as of 26 Oct 2026, 12:42 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in fa465a7819ecbe5801b78c088d3cadaf2664b8ca, 298510bbc7c3017c0faf481c6ea66f1065b657b4, 7fee577a2fa78b9a76da015beec1ccf978746ebb
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
Upgrade Linux kernel to fa465a7819ecbe5801b78c088d3cadaf2664b8ca, 298510bbc7c3017c0faf481c6ea66f1065b657b4 or 7fee577a2fa78b9a76da015beec1ccf978746ebb.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in– |
AI-suggested
A fix is available and has been applied in specific commits referenced by the fixedVersions hashes. The mitigation involves enabling RISCV_ALTERNATIVE_EARLY selection for ERRATA_THEAD_GHOSTWRITE to ensure the vulnerability is detected and mitigated during early boot. Users should update to the fixed kernel versions or apply the corresponding patches to ensure protection.
Description
CVE-2026-99017 is a vulnerability in the Linux kernel affecting RISC-V architectures, specifically related to the THEAD GHOSTWRITE erratum. The issue arises because the mitigation for the ghostwrite vulnerability is only applied during an early boot stage if a specific configuration (CONFIG_RISCV_ALTERNATIVE_EARLY) is enabled. Without this configuration, the system may incorrectly report that it is not affected, leaving the vulnerable CPU unprotected. The fix involves selecting RISCV_ALTERNATIVE_EARLY for ERRATA_THEAD_GHOSTWRITE to ensure detection and mitigation during early boot.