CVE-2026-74456: Linux kernel · can: peak_usb: peak_usb_start(): fix double free of transfer buffer on URB submit error
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 5.15.0-1117.124~20.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 15:59 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 – 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 +28
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 15 Aug 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.
Description
In the Linux kernel, the following vulnerability has been resolved: can: peak_usb: peak_usb_start(): fix double free of transfer buffer on URB submit error In peak_usb_start(), each RX URB transfer buffer is allocated with kmalloc() and the URB is flagged URB_FREE_BUFFER so that the final usb_free_urb() also frees the transfer buffer. If usb_submit_urb() fails, the error path frees the buffer explicitly with kfree(buf) and then calls usb_free_urb(urb). Because URB_FREE_BUFFER is set, usb_free_urb() -> urb_destroy() frees the same buffer a second time, a double free of the transfer buffer. BUG: KASAN: double-free in usb_free_urb.part.0+0x91/0xb0 Free of addr ffff8881069ccb80 by task trigger.sh/285 Call Trace: kfree+0x113/0x3c0 usb_free_urb.part.0+0x91/0xb0 Drop the redundant kfree(buf); usb_free_urb() already releases the transfer buffer. This mirrors commit 03819abbeb11 ("net: usb: lan78xx: Fix double free issue with interrupt buffer allocation").
References
- ubuntu.com/security/CVE-2026-74456 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-74456 (opens in a new tab)
- git.kernel.org/linus/9b3d5a6d952c38bbcf07f903cbeadefdb56b9bc9 (opens in a new tab)
- git.kernel.org/stable/c/4bb3325075138dd5346b71589a959878b564dc0b (opens in a new tab)
- git.kernel.org/stable/c/525640b93d3e5f82f4ebea4730f4e0cf799522ba (opens in a new tab)
- git.kernel.org/stable/c/92d0de80ca2223b9c7da78020155b6cb27824cc0 (opens in a new tab)
- git.kernel.org/stable/c/9b3d5a6d952c38bbcf07f903cbeadefdb56b9bc9 (opens in a new tab)
- git.kernel.org/stable/c/dfb17bf04a764462000f11258a7c06aa92d1f261 (opens in a new tab)
- msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-74456.json (opens in a new tab)
- support.microsoft.com/lifecycle (opens in a new tab)
- first.org/cvss (opens in a new tab)
- ubuntu.com/security/notices/USN-8876-1 (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-8886-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8875-2 (opens in a new tab)