CVE-2026-63904: Linux kernel · usb: usbtmc: check URB actual_length for interrupt-IN notifications
Affects Linux kernelSource GCVE Database
Not known to be exploited · fixed in 5.15.0-1117.124~20.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 14:05 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 13% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +65
Exploitation evidence
Disclosed: evidence found.
CVE published 20 Jul 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 to a fixed release listed under Affected software.
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 patch is available and should be applied to affected Linux Azure kernel versions to resolve this vulnerability. Users should update to versions 7.0.0-28.28 or later, 7.0.0-1009.9 or later, or the corresponding fixed 5.15.0 and 4.x kernel versions. No additional mitigation is indicated by the vendor advisory.
Description
A vulnerability in the Linux kernel's USB Test and Measurement Class (USBTMC) driver was resolved. The issue involved the driver not verifying that interrupt-IN notification messages contained the expected two-byte headers before accessing data buffers. This could lead to out-of-bounds reads or use of stale data when the USB Request Block (URB) actual length was insufficient. The vulnerability affects Linux Azure kernel versions prior to certain 7.0.0 releases. A patch is available and should be applied to mitigate this issue.
References
- nvd.nist.gov/vuln/detail/CVE-2026-63904 (opens in a new tab)
- git.kernel.org/stable/c/52f2ad3f7e5eb3b5908e1d685d4342519dc9cfcd (opens in a new tab)
- git.kernel.org/stable/c/5de7df75ef3a2756b25fe3d582a4a2970444fe5a (opens in a new tab)
- git.kernel.org/stable/c/69020fa089f1bf0e1a10a15265f31b143a846409 (opens in a new tab)
- git.kernel.org/stable/c/75f6d3da2cc646983f41807ef98851569c12bca9 (opens in a new tab)
- git.kernel.org/stable/c/ae87f505917e703ae3b487d9663d78826ff43608 (opens in a new tab)
- git.kernel.org/stable/c/e3eec3005de44e7f37d8d7724be636446516ab42 (opens in a new tab)
- git.kernel.org/stable/c/e794bd67b3faf98af46f958897f6b91412c7d2a9 (opens in a new tab)
- git.kernel.org/stable/c/f141b01eaa58ac7e323931d670318aa247bff087 (opens in a new tab)
- ubuntu.com/security/CVE-2026-63904 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-63904 (opens in a new tab)
- git.kernel.org/linus/52f2ad3f7e5eb3b5908e1d685d4342519dc9cfcd (opens in a new tab)
- ubuntu.com/security/notices/USN-8593-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8603-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8618-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8663-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8664-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8878-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8877-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8875-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8903-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8905-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8906-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8904-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8903-2 (opens in a new tab)