CVE-2026-99236: Linux kernel · tracing: Reject incomplete event filter expressions
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 5 Nov 2026, 00:01 UTC
Thin evidence
One scorer or none| CNA (Linux) | CVSS 3.1 | 7.8 |
|---|
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 2 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 4 Nov 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 for this vulnerability is available. The Linux kernel has been updated to reject incomplete event filter expressions, preventing the out-of-bounds memory access. Users and administrators should apply the official kernel updates corresponding to their affected versions to remediate this issue. No additional mitigations are indicated beyond applying the patch.
Description
CVE-2026-99236 is a high-severity vulnerability in the Linux kernel's tracing subsystem. It involves improper handling of incomplete event filter expressions, which can lead to out-of-bounds memory reads during predicate parsing. This flaw occurs when logical operators at the end of an expression are not properly resolved, potentially causing memory corruption. The issue affects specific Linux kernel versions and has been addressed by rejecting incomplete filter expressions. The vulnerability has a CVSS score of 7.8, indicating a significant impact on confidentiality, integrity, and availability.
References
- ubuntu.com/security/CVE-2026-99236 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-99236 (opens in a new tab)
- git.kernel.org/stable/c/4a1a6d35359991c5d47f4bf101cfbe1475c94093 (opens in a new tab)
- git.kernel.org/stable/c/5a999b5a16530898f0dbe5f8c50fd45ea72e110b (opens in a new tab)
- git.kernel.org/stable/c/15ff3cc7f2beecc3f95d66358f20ad7b057466aa (opens in a new tab)
- git.kernel.org/stable/c/5bcdf3c18c3471122ee9652b0e2f5cdb718d9a46 (opens in a new tab)
- git.kernel.org/stable/c/1008e9e0b8280d47f1ab5e9c113f666a023a9697 (opens in a new tab)
- git.kernel.org/stable/c/b205ff58e02922ac324f931cf9eb238a3acdb048 (opens in a new tab)
- git.kernel.org/stable/c/2a98f5d4913ec081e08e1075512cb7ec313d9f72 (opens in a new tab)
- git.kernel.org/stable/c/64993d970dde2a2da353e9e99595a4fa88ec27d9 (opens in a new tab)