CVE-2026-97587: Linux kernel · perf: RISC-V: store available counter mask as bitmap
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 26 Oct 2026, 14:05 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Exploitation evidence
Disclosed: evidence found.
CVE published 25 Sep 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 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther 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 has been implemented in the Linux kernel to replace the single unsigned long mask with a bitmap for the available counters in the perf subsystem on RISC-V. Users should apply the updated kernel versions that include this fix. Since this is a kernel-level fix, upgrading to patched kernel versions is the recommended remediation.
Description
A vulnerability in the Linux kernel's perf subsystem for RISC-V architecture involved improper handling of the available counter mask. The mask was stored as a single unsigned long, but iteration used a constant RISCV_MAX_COUNTERS set to 64, causing out-of-bounds reads on 32-bit RISC-V (RV32) systems. This was corrected by using a bitmap to properly represent the available counters and updating related code paths accordingly.
References
- ubuntu.com/security/CVE-2026-97587 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-97587 (opens in a new tab)
- git.kernel.org/stable/c/e5481db31f4654e9a1254d5d467d9b1ff2f8b1cb (opens in a new tab)
- git.kernel.org/stable/c/6809da6e9c08ccc9a09cb0a48c61471679274aaa (opens in a new tab)
- git.kernel.org/stable/c/9bec7beaed074bcae4181fde9ff9dfbe4e7b0957 (opens in a new tab)
- git.kernel.org/stable/c/143668c424772979a45118dc9cc9c2c13a35f41d (opens in a new tab)