CVE-2026-90274: Linux kernel · coresight: etm4x: fix underflow for usage of (nrseqstate –
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 26 Oct 2026, 17:16 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Exploitation evidence
Disclosed: evidence found.
CVE published 17 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 address this underflow issue by introducing the nr_seq_ctrls field and ETM_MAX_SEQ_TRANSITIONS macro. Users should apply the updated kernel versions that include this fix. Since this is a kernel-level fix, upgrading to a patched kernel release is the recommended remediation.
Description
A vulnerability in the Linux kernel's coresight etm4x component was resolved that fixed an underflow issue related to the usage of (nrseqstate - 1). This issue arises when the TRCIDR5.NUMSEQSTATE field is 0b000, causing an underflow in a loop that sets TRCSEQEVR<n> fields. The fix involved introducing a separate nr_seq_ctrls field and a macro ETM_MAX_SEQ_TRANSITIONS to properly control the relevant fields setup.
References
- ubuntu.com/security/CVE-2026-90274 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-90274 (opens in a new tab)
- git.kernel.org/linus/1674d9bff8073bdee5dbc200f56fc3caa28d0566 (opens in a new tab)
- msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-90274.json (opens in a new tab)
- support.microsoft.com/lifecycle (opens in a new tab)
- first.org/cvss (opens in a new tab)