CVE-2026-23298: Linux kernel · can: ucan: Fix infinite loop from zero-length messages
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · patch available : update Linux kernel when convenient.
Data as of 26 Oct 2026, 13:47 UTC
- 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.
- Patch
- Available
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 25 Mar 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 25.10linuxpkg:deb/ubuntu/linux@6.17.0-40.40?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws@6.17.0-1019.19?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure@6.17.0-1020.20?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde@6.17.0-1017.17?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp@6.17.0-1020.22?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle@6.17.0-1018.18?arch=source&distro=questingOther 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 patch is available and should be applied to affected linux-hwe-edge kernel versions to resolve this issue. The fix involves skipping zero-length messages in the ucan driver to prevent infinite loops. Users should update to the fixed kernel versions as provided by their vendor.
Description
A vulnerability in the Linux kernel's can: ucan driver could cause an infinite loop when processing zero-length messages from broken ucan devices, leading to system hangs. This issue has been fixed by skipping zero-length messages. The vulnerability affects specific versions of the linux-hwe-edge kernel and has a medium severity rating with a CVSS score of 5.5. A patch is available to address this issue.
References
- ubuntu.com/security/CVE-2026-23298 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-23298 (opens in a new tab)
- git.kernel.org/linus/1e446fd0582ad8be9f6dafb115fc2e7245f9bea7 (opens in a new tab)
- git.kernel.org/stable/c/13b646eec3ba1131180803f5aaf1fee23540ad8f (opens in a new tab)
- git.kernel.org/stable/c/1e446fd0582ad8be9f6dafb115fc2e7245f9bea7 (opens in a new tab)
- git.kernel.org/stable/c/aa9e0a7fe5efc2f74327fd37d828e9a51d9ff588 (opens in a new tab)
- git.kernel.org/stable/c/ab6f075492d37368b4c7b0df7f7fdc2b666887fc (opens in a new tab)
- git.kernel.org/stable/c/bd85f21a6219aeae4389d700c54f1799f4b814e0 (opens in a new tab)
- git.kernel.org/stable/c/c7bc62be6c1a60bb21301692009590b1ffda91d9 (opens in a new tab)
- ubuntu.com/security/notices/USN-8567-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8574-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8575-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8576-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8574-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8595-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8596-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8575-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8576-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8597-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8595-2 (opens in a new tab)